├── .gitignore ├── LICENSE ├── README.md ├── clustering.go ├── foo.txt ├── pocket.csv ├── reader.go ├── results.txt ├── stopwords.csv └── utils ├── get.go └── utils.go /.gitignore: -------------------------------------------------------------------------------- 1 | # Compiled Object files, Static and Dynamic libs (Shared Objects) 2 | *.o 3 | *.a 4 | *.so 5 | 6 | # Folders 7 | _obj 8 | _test 9 | 10 | # Architecture specific extensions/prefixes 11 | *.[568vq] 12 | [568vq].out 13 | 14 | *.cgo1.go 15 | *.cgo2.c 16 | _cgo_defun.c 17 | _cgo_gotypes.go 18 | _cgo_export.* 19 | 20 | _testmain.go 21 | 22 | *.exe 23 | *.test 24 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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The text should be enclosed in the appropriate 184 | comment syntax for the file format. We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright {yyyy} {name of copyright owner} 190 | 191 | Licensed under the Apache License, Version 2.0 (the "License"); 192 | you may not use this file except in compliance with the License. 193 | You may obtain a copy of the License at 194 | 195 | http://www.apache.org/licenses/LICENSE-2.0 196 | 197 | Unless required by applicable law or agreed to in writing, software 198 | distributed under the License is distributed on an "AS IS" BASIS, 199 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 200 | See the License for the specific language governing permissions and 201 | limitations under the License. -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | clustering-golang 2 | ================= 3 | 4 | A personal project to try some clustering features in Go 5 | 6 | Working from this, for now: http://www.public.asu.edu/~salelyan/MyPub/FS4clustering_chapter.pdf 7 | -------------------------------------------------------------------------------- /clustering.go: -------------------------------------------------------------------------------- 1 | // clustering.go 2 | package main 3 | 4 | import ( 5 | "fmt" 6 | "./utils" 7 | "strings" 8 | "math" 9 | ) 10 | 11 | // Returns a map where the key is a word and the int is the number 12 | // of times that word appears in the set of documents 13 | // 14 | // Providing a threshold (1.0 >= x > 0.0) will return only the words 15 | // that appear in all the documents (x*100)% of the time 16 | func termFrequency(recordArray [][]string, threshold float64) (m map[string] int, err error) { 17 | saveMap := make(map[string] map[string] int) 18 | for _, record := range recordArray { 19 | url := record[0] 20 | 21 | if _, ok := saveMap[url]; ok { 22 | continue 23 | } 24 | 25 | words := utils.LowercaseWords(strings.Fields(record[2])) 26 | 27 | for i := range words { 28 | w, err := utils.RemoveNonAlphaNumeric(words[i]) 29 | if err != nil { 30 | continue 31 | } else { 32 | words[i] = w 33 | } 34 | } 35 | 36 | words, err = utils.RemoveStopwords(words) 37 | if err != nil { 38 | return nil, err 39 | } 40 | 41 | saveMap[url] = utils.WordFrequency(words) 42 | } 43 | 44 | documentFrequencyMap := make(map[string] int) 45 | 46 | for _, wordCountMap := range saveMap { 47 | for word := range wordCountMap { 48 | if _, ok := documentFrequencyMap[word]; ok { 49 | documentFrequencyMap[word]++ 50 | } else { 51 | documentFrequencyMap[word] = 1 52 | } 53 | } 54 | } 55 | 56 | if threshold != 0.0 { 57 | for word, value := range documentFrequencyMap { 58 | if float64(value)/float64(len(saveMap)) < threshold { 59 | delete(documentFrequencyMap, word) 60 | } 61 | } 62 | } 63 | return documentFrequencyMap, nil 64 | } 65 | 66 | // Inverse Document Frequency 67 | func inverseDocumentFrequency(recordArray [][]string) (m map[string] float64, err error) { 68 | d := float64(len(recordArray)) 69 | 70 | wordCountMap := make(map[string] int) 71 | for _, record := range recordArray { 72 | words := utils.LowercaseWords(strings.Fields(record[2])) 73 | 74 | for i := range words { 75 | w, err := utils.RemoveNonAlphaNumeric(words[i]) 76 | if err != nil { 77 | continue 78 | } else { 79 | words[i] = w 80 | } 81 | } 82 | 83 | words, err = utils.RemoveStopwords(words) 84 | if err != nil { 85 | return nil, err 86 | } 87 | 88 | words = utils.RemoveDuplicates(words) 89 | 90 | for _, word := range words { 91 | if _, ok := wordCountMap[word]; ok { 92 | wordCountMap[word]++ 93 | } else { 94 | wordCountMap[word] = 1 95 | } 96 | } 97 | } 98 | 99 | idfMap := make(map[string] float64) 100 | for word, value := range wordCountMap { 101 | idfMap[word] = math.Log(d/float64(value)) 102 | } 103 | return idfMap, nil 104 | } 105 | 106 | // Term Frequency-Inverse Document Frequency (TF-IDF) 107 | func termFrequencyInverseDocumentFrequency(fileName string) (m map[string] float64, err error) { 108 | recordArray, err := utils.ReadRecords(fileName) 109 | if err != nil { 110 | return nil, err 111 | } 112 | 113 | tfidfMap := make(map[string] float64) 114 | 115 | tf, err := termFrequency(recordArray, 0.0) 116 | if err != nil { 117 | return nil, err 118 | } 119 | 120 | idf, err := inverseDocumentFrequency(recordArray) 121 | if err != nil { 122 | return nil, err 123 | } 124 | 125 | for word, docFreq := range idf { 126 | tfidfMap[word] = float64(tf[word]) * docFreq 127 | } 128 | return tfidfMap, nil 129 | } 130 | 131 | func main() { 132 | tfidfMap, err := termFrequencyInverseDocumentFrequency("pocket.csv") 133 | if err != nil { 134 | fmt.Println(err) 135 | } else { 136 | for k,v := range tfidfMap { 137 | fmt.Println(k , "->", v ) 138 | } 139 | } 140 | } -------------------------------------------------------------------------------- /foo.txt: -------------------------------------------------------------------------------- 1 | tf–idf 2 | From Wikipedia, the free encyclopedia 3 | (Redirected from Tf-idf) 4 | 5 | This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. Please help to improve this article by introducing more precise citations. (July 2012) 6 | tf–idf, short for term frequency–inverse document frequency, is a numerical statistic that is intended to reflect how important a word is to a document in a collection or corpus.[1]:8 It is often used as a weighting factor in information retrieval and text mining. The tf-idf value increases proportionally to the number of times a word appears in the document, but is offset by the frequency of the word in the corpus, which helps to control for the fact that some words are generally more common than others. 7 | Variations of the tf–idf weighting scheme are often used by search engines as a central tool in scoring and ranking a document's relevance given a user query. tf–idf can be successfully used for stop-words filtering in various subject fields including text summarization and classification. 8 | One of the simplest ranking functions is computed by summing the tf–idf for each query term; many more sophisticated ranking functions are variants of this simple model. 9 | -------------------------------------------------------------------------------- /reader.go: -------------------------------------------------------------------------------- 1 | //I am not a genius. I seek help. This is a cargo-cult code + hacks. 2 | //Source http://stackoverflow.com/a/18479916 3 | package main 4 | 5 | import ( 6 | "bufio" 7 | "fmt" 8 | "log" 9 | "os" 10 | "strings" 11 | "./utils" 12 | ) 13 | 14 | // readLines reads a whole file into memory 15 | // and returns a slice of its lines. 16 | func readLines(path string) (*map[string]uint, error) { 17 | file, err := os.Open(path) 18 | if err != nil { 19 | return nil, err 20 | } 21 | defer file.Close() 22 | 23 | dict := make(map[string]uint) 24 | var lines []string 25 | 26 | scanner := bufio.NewScanner(file) 27 | 28 | for scanner.Scan() { 29 | lines = append(lines, scanner.Text()) 30 | for _, line := range lines { 31 | //TODO Start indexing 32 | words := strings.Split(line," ") 33 | for _ ,word := range words{ 34 | if dict[word] >0 { 35 | dict[word] += 1; 36 | }else{ 37 | dict[word] = 1; 38 | } 39 | } 40 | } 41 | } 42 | 43 | return &dict, scanner.Err() 44 | } 45 | 46 | 47 | 48 | func main() { 49 | queryString := "Neutron" 50 | 51 | fmt.Println(utils.SearchURLPrefix) 52 | links := utils.Scrape(utils.SearchURLPrefix+queryString,utils.Selector) 53 | for k,v := range links{ 54 | fmt.Println(k,utils.GetInfoCardText(v,utils.InfoCardSelector)) 55 | 56 | } 57 | dict, err := readLines("foo.txt") 58 | if err != nil { 59 | log.Fatalf("readLines: %s", err) 60 | }else{ 61 | fmt.Println(*dict) 62 | } 63 | 64 | } -------------------------------------------------------------------------------- /results.txt: -------------------------------------------------------------------------------- 1 | http://en.wikipedia.org/wiki/ 2 | links map[particle:http://en.wikipedia.org/wiki/Elementary_particle fissile:http://en.wikipedia.org/wiki/Fissile hydrogen atom:http://en.wikipedia.org/wiki/Hydrogen_atom CPT-symmetry:http://en.wikipedia.org/wiki/CPT-symmetry neutron transport:http://en.wikipedia.org/wiki/Neutron_transport Faraday effect:http://en.wikipedia.org/wiki/Faraday_effect X-rays:http://en.wikipedia.org/wiki/X-rays nuclear force:http://en.wikipedia.org/wiki/Nuclear_force Thermal neutrons:http://en.wikipedia.org/wiki/Thermal_neutron Ultracold neutrons:http://en.wikipedia.org/wiki/Ultracold_neutrons reactor grade plutonium:http://en.wikipedia.org/wiki/Reactor_grade_plutonium nuclide:http://en.wikipedia.org/wiki/Nuclide californium:http://en.wikipedia.org/wiki/Californium radiation:http://en.wikipedia.org/wiki/Radiation baryon number:http://en.wikipedia.org/wiki/Baryon_number electric dipole moment:http://en.wikipedia.org/wiki/Electric_dipole_moment velocity selection:http://en.wikipedia.org/wiki/Neutron-velocity_selector photons:http://en.wikipedia.org/wiki/Photon uranium-235:http://en.wikipedia.org/wiki/Uranium-235 ln:http://en.wikipedia.org/wiki/Natural_logarithm J:http://en.wikipedia.org/wiki/Joule molecules:http://en.wikipedia.org/wiki/Molecules neutron moderator:http://en.wikipedia.org/wiki/Neutron_moderator mode:http://en.wikipedia.org/wiki/Mode_(statistics) condensed matter:http://en.wikipedia.org/wiki/Condensed_matter bremsstrahlung:http://en.wikipedia.org/wiki/Bremsstrahlung Nuclear fission reactors:http://en.wikipedia.org/wiki/Nuclear_reactor nuclear reactor:http://en.wikipedia.org/wiki/Nuclear_reactor nuclear proliferation:http://en.wikipedia.org/wiki/Nuclear_proliferation diproton:http://en.wikipedia.org/wiki/Diproton nuclear fusion reactors:http://en.wikipedia.org/wiki/Fusion_power neutron's magnetic moment:http://en.wikipedia.org/wiki/Neutron_magnetic_moment neutron scattering:http://en.wikipedia.org/wiki/Neutron_scattering spontaneous fission:http://en.wikipedia.org/wiki/Spontaneous_fission neutron capture:http://en.wikipedia.org/wiki/Neutron_capture hydrogen-1:http://en.wikipedia.org/wiki/Hydrogen-1 beyond the Standard Model:http://en.wikipedia.org/wiki/Beyond_the_Standard_Model nuclear transmutations:http://en.wikipedia.org/wiki/Nuclear_transmutation spallation sources:http://en.wikipedia.org/wiki/Spallation neutron emission:http://en.wikipedia.org/wiki/Neutron_emission fission reactors:http://en.wikipedia.org/wiki/Nuclear_reactor tokamak:http://en.wikipedia.org/wiki/Tokamak carbon-12:http://en.wikipedia.org/wiki/Carbon-12 electron antineutrino:http://en.wikipedia.org/wiki/Electron_neutrino polonium:http://en.wikipedia.org/wiki/Polonium gamma radiation:http://en.wikipedia.org/wiki/Gamma_radiation down quarks:http://en.wikipedia.org/wiki/Down_quark fusion:http://en.wikipedia.org/wiki/Nuclear_fusion flavour:http://en.wikipedia.org/wiki/Flavour_(physics) cosmic rays:http://en.wikipedia.org/wiki/Cosmic_ray alpha particles:http://en.wikipedia.org/wiki/Alpha_particle weak interaction:http://en.wikipedia.org/wiki/Weak_interaction ordinary water:http://en.wikipedia.org/wiki/Water kinetic theory:http://en.wikipedia.org/wiki/Kinetic_theory nuclear weapon design:http://en.wikipedia.org/wiki/Nuclear_weapon_design fertile:http://en.wikipedia.org/wiki/Fertile_material heavy water:http://en.wikipedia.org/wiki/Heavy_water fertile materials:http://en.wikipedia.org/wiki/Fertile_material reactivity:http://en.wikipedia.org/wiki/Nuclear_chain_reaction Irène Joliot-Curie:http://en.wikipedia.org/wiki/Ir%C3%A8ne_Joliot-Curie e:http://en.wikipedia.org/wiki/Elementary_charge tetraneutrons:http://en.wikipedia.org/wiki/Tetraneutrons electric charge:http://en.wikipedia.org/wiki/Electric_charge nuclear fission:http://en.wikipedia.org/wiki/Nuclear_fission neutron sources:http://en.wikipedia.org/wiki/Neutron_source irradiation:http://en.wikipedia.org/wiki/Irradiation Viktor Ambartsumian:http://en.wikipedia.org/wiki/Viktor_Ambartsumian Planck constant:http://en.wikipedia.org/wiki/Planck_constant electron capture:http://en.wikipedia.org/wiki/Electron_capture transmutation:http://en.wikipedia.org/wiki/Nuclear_transmutation neutron facility:http://en.wikipedia.org/wiki/Neutron_facilities quarks:http://en.wikipedia.org/wiki/Quark cloud chamber:http://en.wikipedia.org/wiki/Cloud_chamber magnetic fields:http://en.wikipedia.org/wiki/Magnetic_field gamma rays:http://en.wikipedia.org/wiki/Gamma_ray thorium cycle:http://en.wikipedia.org/wiki/Thorium_cycle nucleons:http://en.wikipedia.org/wiki/Nucleon spallation:http://en.wikipedia.org/wiki/Spallation knocking them loose from nuclei:http://en.wikipedia.org/wiki/Spallation#Nuclear_spallation nuclear weapons:http://en.wikipedia.org/wiki/Nuclear_weapon standard deviations:http://en.wikipedia.org/wiki/Standard_deviation Cross sections:http://en.wikipedia.org/wiki/Cross_section_(physics) cell:http://en.wikipedia.org/wiki/Cell_(biology) mean lifetime:http://en.wikipedia.org/wiki/Mean_lifetime unsolved puzzles in particle physics:http://en.wikipedia.org/wiki/List_of_unsolved_problems_in_physics#High_energy_physics neutrino:http://en.wikipedia.org/wiki/Neutrino neutron probe:http://en.wikipedia.org/wiki/Neutron_probe speed of light:http://en.wikipedia.org/wiki/Speed_of_light transient:http://en.wikipedia.org/wiki/Transient_state_(chemical_engineering) up quark:http://en.wikipedia.org/wiki/Up_quark paraffin:http://en.wikipedia.org/wiki/Paraffin_wax USSR:http://en.wikipedia.org/wiki/USSR unstable:http://en.wikipedia.org/wiki/Unstable_isotope graphite:http://en.wikipedia.org/wiki/Graphite heavy nuclei:http://en.wikipedia.org/wiki/Actinides Boltzmann distributed:http://en.wikipedia.org/wiki/Maxwell%E2%80%93Boltzmann_distribution nuclear fuels:http://en.wikipedia.org/wiki/Nuclear_fuel W boson:http://en.wikipedia.org/wiki/W_boson fissionable:http://en.wikipedia.org/wiki/Fissionable plutonium-239:http://en.wikipedia.org/wiki/Plutonium-239 Cosmic radiation:http://en.wikipedia.org/wiki/Cosmic_ray neutron radiation:http://en.wikipedia.org/wiki/Neutron_radiation moderated:http://en.wikipedia.org/wiki/Neutron_moderator research reactors:http://en.wikipedia.org/wiki/Research_reactor antiparticle:http://en.wikipedia.org/wiki/Antiparticle citation needed:http://en.wikipedia.org/wiki/Wikipedia:Citation_needed proton:http://en.wikipedia.org/wiki/Proton James Chadwick:http://en.wikipedia.org/wiki/James_Chadwick antielectron:http://en.wikipedia.org/wiki/Antielectron magnetic:http://en.wikipedia.org/wiki/Magnet moderate:http://en.wikipedia.org/wiki/Neutron_moderator nuclear chain reaction:http://en.wikipedia.org/wiki/Nuclear_chain_reaction MeV:http://en.wikipedia.org/wiki/MeV fusion reaction:http://en.wikipedia.org/wiki/D-T_fusion Standard Model of particle physics:http://en.wikipedia.org/wiki/Standard_Model Standard Model:http://en.wikipedia.org/wiki/Standard_Model antimony-124:http://en.wikipedia.org/wiki/Antimony-124 cross sections:http://en.wikipedia.org/wiki/Cross_section_(physics) be captured without causing fission or spallation:http://en.wikipedia.org/wiki/Neutron_capture subatomic:http://en.wikipedia.org/wiki/Subatomic_particle actinide:http://en.wikipedia.org/wiki/Actinide research reactor:http://en.wikipedia.org/wiki/Research_reactor Pauli exclusion principle:http://en.wikipedia.org/wiki/Pauli_exclusion_principle dineutron:http://en.wikipedia.org/wiki/Dineutron radioactive decay:http://en.wikipedia.org/wiki/Radioactive_decay deuterium:http://en.wikipedia.org/wiki/Deuterium atoms:http://en.wikipedia.org/wiki/Atom electron:http://en.wikipedia.org/wiki/Electron Ernest Rutherford:http://en.wikipedia.org/wiki/Ernest_Rutherford quantum mechanics:http://en.wikipedia.org/wiki/Quantum_mechanics Frédéric Joliot:http://en.wikipedia.org/wiki/Fr%C3%A9d%C3%A9ric_Joliot chain reaction:http://en.wikipedia.org/wiki/Chain_reaction joules:http://en.wikipedia.org/wiki/Joule neutronium:http://en.wikipedia.org/wiki/Neutronium Walther Bothe:http://en.wikipedia.org/wiki/Walther_Bothe boron:http://en.wikipedia.org/wiki/Boron hydrogen:http://en.wikipedia.org/wiki/Hydrogen University of Cambridge:http://en.wikipedia.org/wiki/University_of_Cambridge charged:http://en.wikipedia.org/wiki/Electric_charge Dmitri Ivanenko:http://en.wikipedia.org/wiki/Dmitri_Ivanenko alpha decay:http://en.wikipedia.org/wiki/Alpha_decay alpha particle:http://en.wikipedia.org/wiki/Alpha_particle carbon-14:http://en.wikipedia.org/wiki/Carbon-14 annihilate:http://en.wikipedia.org/wiki/Annihilation elastic scattering:http://en.wikipedia.org/wiki/Elastic_scattering Cold, thermal and hot:http://en.wikipedia.org/wiki/Neutron_temperature boron capture therapy:http://en.wikipedia.org/wiki/Neutron_capture_therapy_of_cancer free neutron:http://en.wikipedia.org/wiki/Free_neutron thermonuclear weapons:http://en.wikipedia.org/wiki/Thermonuclear_weapon beta decay:http://en.wikipedia.org/wiki/Beta_decay helium:http://en.wikipedia.org/wiki/Helium helium-3:http://en.wikipedia.org/wiki/Helium-3 Nuclear reaction:http://en.wikipedia.org/wiki/Nuclear_reaction bore holes:http://en.wikipedia.org/wiki/Bore_hole capture:http://en.wikipedia.org/wiki/Neutron_capture neutron-proton ratio:http://en.wikipedia.org/wiki/Neutron-proton_ratio reflection:http://en.wikipedia.org/wiki/Neutron_reflector fast breeder:http://en.wikipedia.org/wiki/Fast_breeder Latin:http://en.wikipedia.org/wiki/Latin atomic nuclei:http://en.wikipedia.org/wiki/Atomic_nucleus lithium:http://en.wikipedia.org/wiki/Lithium neutron activation:http://en.wikipedia.org/wiki/Neutron_activation boron-10:http://en.wikipedia.org/wiki/Boron-10 resonance:http://en.wikipedia.org/wiki/Resonance neutron number:http://en.wikipedia.org/wiki/Neutron_number neutron stars:http://en.wikipedia.org/wiki/Neutron_star magnetic mirrors:http://en.wikipedia.org/wiki/Magnetic_mirror electromagnetic repulsion:http://en.wikipedia.org/wiki/Electromagnetic_interaction Chicago Pile-1:http://en.wikipedia.org/wiki/Chicago_Pile-1 decay energy:http://en.wikipedia.org/wiki/Decay_energy gamma ray:http://en.wikipedia.org/wiki/Gamma_ray lithium-7:http://en.wikipedia.org/wiki/Lithium-7 chemical element:http://en.wikipedia.org/wiki/Chemical_element particle accelerators:http://en.wikipedia.org/wiki/Particle_accelerator fission:http://en.wikipedia.org/wiki/Nuclear_fission nuclear interaction:http://en.wikipedia.org/wiki/Strong_force atom:http://en.wikipedia.org/wiki/Atom electric:http://en.wikipedia.org/wiki/Electric_field mass:http://en.wikipedia.org/wiki/Mass moderation:http://en.wikipedia.org/wiki/Neutron_moderator change:http://en.wikipedia.org/wiki/Flavour_changing_processes hyperfine structure:http://en.wikipedia.org/wiki/Hyperfine_structure nuclear reactions:http://en.wikipedia.org/wiki/Nuclear_reaction prompt gamma neutron activation analysis:http://en.wikipedia.org/wiki/Prompt_gamma_neutron_activation_analysis kinetic energy:http://en.wikipedia.org/wiki/Kinetic_energy Greek:http://en.wikipedia.org/wiki/Greek_language eV:http://en.wikipedia.org/wiki/Electronvolt light water:http://en.wikipedia.org/wiki/Light_water_reactor inverse beta decay:http://en.wikipedia.org/wiki/Inverse_beta_decay Maxwell–Boltzmann distribution:http://en.wikipedia.org/wiki/Maxwell%E2%80%93Boltzmann_distribution uranium-233:http://en.wikipedia.org/wiki/Uranium-233 beryllium:http://en.wikipedia.org/wiki/Beryllium radioisotope:http://en.wikipedia.org/wiki/Radioisotope nuclear reactors:http://en.wikipedia.org/wiki/Nuclear_reactor cause more fission:http://en.wikipedia.org/wiki/Fusion_boosting thermal reactor:http://en.wikipedia.org/wiki/Thermal_reactor protons:http://en.wikipedia.org/wiki/Proton ionization:http://en.wikipedia.org/wiki/Ionization half-life:http://en.wikipedia.org/wiki/Half-life Bruce Cork:http://en.wikipedia.org/wiki/Bruce_Cork neutron activation analysis:http://en.wikipedia.org/wiki/Neutron_activation_analysis fast neutron reactor:http://en.wikipedia.org/wiki/Fast_neutron_reactor antiproton:http://en.wikipedia.org/wiki/Antiproton gamma decay:http://en.wikipedia.org/wiki/Gamma_decay beta particles:http://en.wikipedia.org/wiki/Beta_particle lead:http://en.wikipedia.org/wiki/Lead CANDU:http://en.wikipedia.org/wiki/CANDU tritium:http://en.wikipedia.org/wiki/Tritium nucleus:http://en.wikipedia.org/wiki/Atomic_nucleus depleted uranium:http://en.wikipedia.org/wiki/Depleted_uranium isotope:http://en.wikipedia.org/wiki/Isotope neutron generators:http://en.wikipedia.org/wiki/Neutron_generator cross section:http://en.wikipedia.org/wiki/Cross_section_(physics) radioactivity:http://en.wikipedia.org/wiki/Radioactivity fissioning:http://en.wikipedia.org/wiki/Nuclear_fission hadron:http://en.wikipedia.org/wiki/Hadron] 3 | infocard 4 | Neutron 5 | 6 | 7 | The quark structure of the neutron. (The color assignment of individual quarks is not important, only that all three colors are present.) 8 | 9 | 10 | 11 | Classification 12 | Baryon 13 | 14 | 15 | Composition 16 | 1 up quark, 2 down quarks 17 | 18 | 19 | Statistics 20 | Fermionic 21 | 22 | 23 | Interactions 24 | Gravity, Weak, Strong, Electromagnetic 25 | 26 | 27 | Symbol 28 | n, n0, N0 29 | 30 | 31 | Antiparticle 32 | Antineutron 33 | 34 | 35 | Theorized 36 | Ernest Rutherford[1][2] (1920) 37 | 38 | 39 | Discovered 40 | James Chadwick[1] (1932) 41 | 42 | 43 | Mass 44 | 1.674927351(74)×10−27 kg[3] 45 | 939.565378(21) MeV/c2[3] 46 | 1.00866491600(43) u[3] 47 | 48 | 49 | Mean lifetime 50 | 881.5(15) s (free) 51 | 52 | 53 | Electric charge 54 | 0 e 55 | 0 C 56 | 57 | 58 | Electric dipole moment 59 | < 2.9×10−26 e·cm 60 | 61 | 62 | Electric polarizability 63 | 1.16(15)×10−3 fm3 64 | 65 | 66 | Magnetic moment 67 | −0.96623647(23)×10−26 J·T−1[3] 68 | −1.04187563(25)×10−3 μB[3] 69 | −1.91304272(45) μN[3] 70 | 71 | 72 | Magnetic polarizability 73 | 3.7(20)×10−4 fm3 74 | 75 | 76 | Spin 77 | 1⁄2 78 | 79 | 80 | Isospin 81 | 1⁄2 82 | 83 | 84 | Parity 85 | +1 86 | 87 | 88 | Condensed 89 | I(JP) = 1⁄2(1⁄2+) 90 | 91 | 92 | map[used:7 weighting:5 and:7 engines:2 intended:3 others.:3 simplest:1 inline:4 or:3 can:2 :17 references,:4 2012):4 sophisticated:1 term:3 document:6 reflect:3 It:3 central:2 includes:4 Please:4 is:16 words:3 scoring:2 number:3 times:3 control:3 common:3 ranking:4 (Redirected:6 introducing:4 query:1 tool:2 functions:2 each:1 classification.:2 One:1 model.:1 its:4 statistic:3 tf-idf:3 which:3 including:2 information:3 helps:3 the:29 Tf-idf):6 has:4 (July:4 fields:2 a:28 tf–idf,:3 text:5 offset:3 corpus,:3 to:16 frequency,:3 numerical:3 that:6 collection:3 retrieval:3 given:2 subject:2 many:1 encyclopedia:7 this:5 successfully:2 as:5 term;:1 precise:4 The:3 scheme:2 user:2 from:6 it:4 often:5 increases:3 are:6 variants:1 word:9 generally:3 Variations:2 document's:2 filtering:2 search:2 relevance:2 Wikipedia,:7 more:8 frequency–inverse:3 value:3 frequency:3 list:4 unclear:4 because:4 fact:3 query.:2 insufficient:4 help:4 how:3 factor:3 From:7 remain:4 simple:1 short:3 than:3 some:3 be:2 stop-words:2 various:2 of:14 sources:4 by:10 tf–idf:13 This:4 article:8 corpus.[1]:8:3 computed:1 summarization:2 summing:1 free:7 citations.:8 improve:4 important:3 appears:3 document,:3 but:7 for:9 in:16 mining.:3 proportionally:3] 93 | http://en.wikipedia.org/wiki/ 94 | Dmitri Ivanenko 95 | 96 | Dmitri Ivanenko 97 | 98 | 99 | Born 100 | (1904-07-29)29 July 1904 101 | Poltava, Russian Empire 102 | 103 | 104 | Died 105 | December 30, 1994(1994-12-30) (aged 90) 106 | Moscow, Russia 107 | 108 | 109 | Citizenship 110 | USSR 111 | Russia 112 | 113 | 114 | Nationality 115 | Russia 116 | 117 | 118 | Fields 119 | Theoretical physics 120 | Nuclear physics 121 | Field theory 122 | Gravitation 123 | 124 | 125 | Institutions 126 | Moscow State University 127 | 128 | 129 | Alma mater 130 | Leningrad State University 131 | 132 | 133 | Doctoral students 134 | Arseny Sokolov 135 | Gennadi Sardanashvily 136 | 137 | 138 | antiparticle 139 | gamma decay 140 | diproton 141 | heavy water 142 | 143 | Heavy water 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | IUPAC name 152 | 153 | [2H]2-Water[citation needed] 154 | 155 | 156 | 157 | 158 | 159 | 160 | 161 | Other names 162 | 163 | 164 | 165 | 166 | Deuterium monoxide[citation needed] 167 | Deuterium oxide[citation needed] 168 | Water-d2[citation needed] 169 | 170 | 171 | 172 | 173 | 174 | 175 | 176 | Identifiers 177 | 178 | 179 | CAS number 180 | 7789-20-0 Y 181 | 182 | 183 | PubChem 184 | 24602 185 | 186 | 187 | ChemSpider 188 | 23004 Y 189 | 190 | 191 | UNII 192 | J65BV539M3 Y 193 | 194 | 195 | EC number 196 | 232-148-9 197 | 198 | 199 | KEGG 200 | D03703 Y 201 | 202 | 203 | MeSH 204 | Deuterium+Oxide 205 | 206 | 207 | ChEBI 208 | CHEBI:41981 Y 209 | 210 | 211 | RTECS number 212 | ZC0230000 213 | 214 | 215 | Gmelin Reference 216 | 97 217 | 218 | 219 | Jmol-3D images 220 | Image 1 221 | 222 | 223 | 224 | 225 | 226 | SMILES 227 | 228 | 229 | 230 | [2H]O[2H] 231 | 232 | 233 | 234 | 235 | 236 | 237 | 238 | 239 | 240 | 241 | 242 | 243 | InChI 244 | 245 | 246 | 247 | InChI=1S/H2O/h1H2/i/hD2 Y 248 | Key: XLYOFNOQVPJJNP-ZSJDYOACSA-N Y 249 | 250 | 251 | 252 | 253 | 254 | 255 | Properties 256 | 257 | 258 | Molecular formula 259 | D 260 | 2O 261 | 262 | 263 | Molar mass 264 | 20.0276 g mol−1 265 | 266 | 267 | Appearance 268 | Very pale blue, transparent liquid 269 | 270 | 271 | Odor 272 | Odorless 273 | 274 | 275 | Density 276 | 1.107 g mL−1 277 | 278 | 279 | Melting point 280 | 3.82 °C; 38.88 °F; 276.97 K 281 | 282 | 283 | Boiling point 284 | 101.4 °C (214.5 °F; 374.5 K) 285 | 286 | 287 | Solubility in water 288 | Soluble 289 | 290 | 291 | log P 292 | −1.38 293 | 294 | 295 | Refractive index (nD) 296 | 1.328 297 | 298 | 299 | Viscosity 300 | 1.25 mPa s (at 20 °C) 301 | 302 | 303 | Dipole moment 304 | 1.87 D 305 | 306 | 307 | Hazards 308 | 309 | 310 | NFPA 704 311 | 312 | 313 | 314 | 315 | 316 | 317 | 318 | 319 | 320 | 321 | 322 | 0 323 | 1 324 | 1 325 | 326 | 327 | 328 | 329 | 330 | 331 | Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) 332 | 333 | 334 |  Y (verify) (what is: Y/N?) 335 | 336 | 337 | Infobox references 338 | 339 | 340 | 341 | 342 | 343 | 344 | nuclear proliferation 345 | cell 346 | 347 | Cell 348 | 349 | 350 | 351 | Onion (Allium) cells in different phases of the cell cycle 352 | 353 | 354 | 355 | 356 | The cells of eukaryotes (left) and prokaryotes (right) 357 | 358 | 359 | 360 | elastic scattering 361 | nuclear weapon design 362 | MeV 363 | radioactivity 364 | lead 365 | 366 | NFPA 704 367 | fire diamond 368 | 369 | 370 | 371 | 372 | 373 | 374 | 375 | 376 | 377 | 378 | 379 | 380 | 381 | 1 382 | 3 383 | 0 384 | 385 | 386 | 387 | 388 | 389 | 390 | Fire diamond for lead granules 391 | 392 | 393 | helium 394 | Listen to this article (info/dl) 395 | 396 | 397 | Sorry, your browser either has JavaScript disabled or does not have any supported player. 398 | You can download the clip or download a player to play the clip in your browser. 399 | 400 | 401 | 402 | 403 | 404 | 405 | This audio file was created from a revision of the "Helium" article dated 2009-07-15, and does not reflect subsequent edits to the article. (Audio help) 406 | More spoken articles 407 | 408 | nuclide 409 | gamma ray 410 | electric 411 | bore holes 412 | helium-3 413 | Standard Model of particle physics 414 | Ernest Rutherford 415 | 416 | The Right Honourable 417 | The Lord Rutherford of Nelson 418 | FRS OM 419 | 420 | 421 | 422 | Lord Rutherford of Nelson 423 | 424 | 425 | 426 | Born 427 | (1871-08-30)30 August 1871 428 | Brightwater, Tasman District, New Zealand 429 | 430 | 431 | Died 432 | 19 October 1937(1937-10-19) (aged 66) 433 | Cambridge, England, UK 434 | 435 | 436 | Residence 437 | New Zealand, United Kingdom 438 | 439 | 440 | Citizenship 441 | New Zealand, United Kingdom 442 | 443 | 444 | Fields 445 | Physics and Chemistry 446 | 447 | 448 | Institutions 449 | McGill University 450 | University of Manchester 451 | 452 | 453 | Alma mater 454 | University of Canterbury 455 | University of Cambridge 456 | 457 | 458 | Academic advisors 459 | Alexander Bickerton 460 | J. J. Thomson 461 | 462 | 463 | Doctoral students 464 | Nazir Ahmed 465 | Norman Alexander 466 | Edward Victor Appleton 467 | Robert William Boyle 468 | Rafi Muhammad Chaudhry 469 | Alexander MacAulay 470 | Cecil Powell 471 | Henry DeWolf Smyth 472 | Ernest Walton 473 | C. E. Wynn-Williams 474 | Yulii Borisovich Khariton 475 | 476 | 477 | Other notable students 478 | Edward Andrade 479 | Edward Victor Appleton 480 | Patrick Blackett 481 | Niels Bohr 482 | Bertram Boltwood 483 | Harriet Brooks 484 | Teddy Bullard 485 | James Chadwick 486 | John Cockcroft 487 | Charles Galton Darwin 488 | Charles Drummond Ellis 489 | Kazimierz Fajans 490 | Hans Geiger 491 | Otto Hahn 492 | Douglas Hartree 493 | Pyotr Kapitsa 494 | George Laurence 495 | Iven Mackay 496 | Ernest Marsden 497 | Mark Oliphant 498 | Thomas Royds 499 | Frederick Soddy 500 | 501 | 502 | Known for 503 | Father of nuclear physics 504 | Rutherford model 505 | Rutherford scattering 506 | Rutherford backscattering spectroscopy 507 | Discovery of proton 508 | Rutherford (unit) 509 | Coining the term 'artificial disintegration' 510 | 511 | 512 | Influenced 513 | Henry Moseley 514 | Hans Geiger 515 | Albert Beaumont Wood 516 | 517 | 518 | Notable awards 519 | Rumford Medal (1904) 520 | Nobel Prize in Chemistry (1908) 521 | Elliott Cresson Medal (1910) 522 | Matteucci Medal (1913) 523 | Copley Medal (1922) 524 | Franklin Medal (1924) 525 | Albert Medal (1928) 526 | Faraday Medal (1930) 527 | 528 | 529 | Signature 530 | 531 | 532 | 533 | atomic nuclei 534 | paraffin 535 | hyperfine structure 536 | decay energy 537 | irradiation 538 | CPT-symmetry 539 | nuclear fuels 540 | proton 541 | Proton 542 | 543 | 544 | The quark structure of the proton. (The color assignment of individual quarks is not important, only that all three colors are present.) 545 | 546 | 547 | 548 | Classification 549 | Baryon 550 | 551 | 552 | Composition 553 | 2 up quarks, 1 down quark 554 | 555 | 556 | Statistics 557 | Fermionic 558 | 559 | 560 | Interactions 561 | Gravity, Electromagnetic, Weak, Strong 562 | 563 | 564 | Symbol 565 | p, p+, N+ 566 | 567 | 568 | Antiparticle 569 | Antiproton 570 | 571 | 572 | Theorized 573 | William Prout (1815) 574 | 575 | 576 | Discovered 577 | Ernest Rutherford (1917–1919, named by him, 1920) 578 | 579 | 580 | Mass 581 | 582 | 1.672621777(74)×10−27 kg[1] 583 | 938.272046(21) MeV/c2[1] 584 | 1.007276466812(90) u[1] 585 | 586 | 587 | Mean lifetime 588 | >2.1×1029 years (stable) 589 | 590 | 591 | Electric charge 592 | +1 e 593 | 1.602176565(35)×10−19 C[1] 594 | 595 | 596 | Charge radius 597 | 0.8775(51) fm[1] 598 | 599 | 600 | Electric dipole moment 601 | <5.4×10−24 e·cm 602 | 603 | 604 | Electric polarizability 605 | 1.20(6)×10−3 fm3 606 | 607 | 608 | Magnetic moment 609 | 610 | 1.410606743(33)×10−26 J·T−1[1] 611 | 1.521032210(12)×10−3 μB[1] 612 | 2.792847356(23) μN[1] 613 | 614 | 615 | Magnetic polarizability 616 | 1.9(5)×10−4 fm3 617 | 618 | 619 | Spin 620 | 1⁄2 621 | 622 | 623 | Isospin 624 | 1⁄2 625 | 626 | 627 | Parity 628 | +1 629 | 630 | 631 | Condensed 632 | I(JP) = 1⁄2(1⁄2+) 633 | 634 | 635 | Cosmic radiation 636 | Ultracold neutrons 637 | hydrogen 638 | Listen to this article (2 parts) · (info) 639 | Part 1 • Part 2 640 | 641 | 642 | 643 | This audio file was created from a revision of the "Hydrogen" article dated 2006-10-28, and does not reflect subsequent edits to the article. (Audio help) 644 | More spoken articles 645 | 646 | electromagnetic repulsion 647 | 648 | Library resources about 649 | Electromagnetism 650 | 651 | 652 | 653 | 654 | 655 | Resources in your library 656 | 657 | 658 | 659 | 660 | be captured without causing fission or spallation 661 | fertile 662 | neutron sources 663 | ln 664 | 665 | Natural Logarithm 666 | 667 | 668 | Representation 669 | 670 | 671 | 672 | Inverse 673 | 674 | 675 | 676 | Derivative 677 | 678 | 679 | 680 | Indefinite Integral 681 | 682 | 683 | 684 | Nuclear fission reactors 685 | neutron facility 686 | eV 687 | kinetic energy 688 | 689 | Kinetic energy 690 | 691 | 692 | 693 | The cars of a roller coaster reach their maximum kinetic energy when at the bottom of their path. When they start rising, the kinetic energy begins to be converted to gravitational potential energy. The sum of kinetic and potential energy in the system remains constant, ignoring losses to friction. 694 | 695 | 696 | 697 | Common symbols 698 | KE, Ek, or T 699 | 700 | 701 | SI unit 702 | joule (J) 703 | 704 | 705 | Derivations from 706 | other quantities 707 | 708 | Ek = ½mv2 709 | Ek = Et+Er 710 | 711 | 712 | Viktor Ambartsumian 713 | 714 | Victor Ambartsumian 715 | 716 | 717 | 718 | 719 | 720 | Born 721 | (1908-09-18)September 18, 1908 722 | Tiflis, Russian Empire 723 | (modern-day Tbilisi, Georgia) 724 | 725 | 726 | Died 727 | August 12, 1996(1996-08-12) (aged 87) 728 | Byurakan, Armenia 729 | 730 | 731 | Nationality 732 | Soviet, Armenian 733 | 734 | 735 | Fields 736 | theoretical astrophysics 737 | 738 | 739 | Notable awards 740 | Lomonosov Gold Medal (1971) 741 | 742 | 743 | research reactor 744 | knocking them loose from nuclei 745 | neutron-proton ratio 746 | californium 747 | 748 | Californium 749 | 750 | 751 | 98Cf 752 | 753 | 754 | 755 | 756 | 757 | 758 | 759 | 760 | 761 | 762 | 763 | 764 | 765 | 766 | 767 | 768 | 769 | 770 | 771 | 772 | 773 | 774 | 775 | 776 | 777 | 778 | 779 | 780 | 781 | 782 | 783 | 784 | 785 | 786 | 787 | 788 | 789 | 790 | 791 | 792 | 793 | 794 | 795 | 796 | 797 | 798 | 799 | 800 | 801 | 802 | 803 | 804 | 805 | 806 | 807 | 808 | 809 | 810 | 811 | 812 | 813 | 814 | 815 | 816 | 817 | 818 | 819 | 820 | 821 | 822 | 823 | 824 | 825 | 826 | 827 | 828 | 829 | 830 | 831 | 832 | 833 | 834 | 835 | 836 | 837 | 838 | 839 | 840 | 841 | 842 | 843 | 844 | 845 | 846 | 847 | 848 | 849 | 850 | 851 | 852 | 853 | 854 | 855 | 856 | 857 | 858 | 859 | 860 | 861 | 862 | 863 | 864 | 865 | 866 | 867 | 868 | 869 | 870 | 871 | 872 | 873 | 874 | 875 | 876 | 877 | 878 | 879 | 880 | 881 | 882 | 883 | 884 | 885 | 886 | 887 | 888 | 889 | 890 | 891 | 892 | 893 | 894 | 895 | 896 | 897 | 898 | 899 | 900 | 901 | 902 | 903 | 904 | 905 | 906 | 907 | 908 | 909 | 910 | 911 | 912 | 913 | 914 | 915 | 916 | 917 | 918 | 919 | 920 | 921 | 922 | 923 | 924 | 925 | 926 | 927 | 928 | 929 | 930 | 931 | 932 | 933 | 934 | 935 | 936 | 937 | 938 | 939 | 940 | 941 | 942 | 943 | 944 | 945 | 946 | 947 | 948 | 949 | 950 | 951 | 952 | 953 | 954 | 955 | 956 | 957 | 958 | 959 | 960 | 961 | 962 | 963 | 964 | 965 | 966 | 967 | 968 | 969 | 970 | 971 | 972 | 973 | 974 | 975 | 976 | 977 | 978 | 979 | 980 | 981 | 982 | 983 | 984 | 985 | 986 | 987 | 988 | 989 | 990 | 991 | 992 | 993 | 994 | 995 | 996 | 997 | 998 | 999 | 1000 | 1001 | 1002 | 1003 | 1004 | 1005 | 1006 | 1007 | 1008 | 1009 | 1010 | 1011 | 1012 | 1013 | 1014 | 1015 | 1016 | 1017 | 1018 | 1019 | 1020 | 1021 | 1022 | 1023 | 1024 | 1025 | 1026 | 1027 | 1028 | 1029 | 1030 | 1031 | 1032 | 1033 | 1034 | 1035 | 1036 | 1037 | 1038 | 1039 | 1040 | 1041 | 1042 | 1043 | 1044 | 1045 | 1046 | 1047 | 1048 | 1049 | 1050 | 1051 | 1052 | 1053 | 1054 | 1055 | 1056 | 1057 | 1058 | 1059 | 1060 | 1061 | 1062 | 1063 | 1064 | 1065 | 1066 | 1067 | 1068 | 1069 | 1070 | 1071 | 1072 | 1073 | 1074 | 1075 | 1076 | 1077 | 1078 | 1079 | 1080 | 1081 | 1082 | 1083 | 1084 | 1085 | 1086 | 1087 | 1088 | 1089 | 1090 | 1091 | 1092 | 1093 | 1094 | 1095 | 1096 | 1097 | 1098 | 1099 | 1100 | 1101 | 1102 | 1103 | 1104 | 1105 | 1106 | 1107 | 1108 | 1109 | 1110 | 1111 | 1112 | 1113 | 1114 | 1115 | 1116 | 1117 | 1118 | 1119 | 1120 | 1121 | 1122 | 1123 | 1124 | 1125 | 1126 | 1127 | 1128 | 1129 | 1130 | 1131 | 1132 | 1133 | 1134 | 1135 | 1136 | 1137 | 1138 | Dy 1139 | ↑ 1140 | Cf 1141 | ↓ 1142 | (Upn) 1143 | 1144 | 1145 | berkelium ← californium → einsteinium 1146 | 1147 | 1148 | 1149 | 1150 | 1151 | 1152 | 1153 | 1154 | Californium in the periodic table 1155 | 1156 | 1157 | Appearance 1158 | 1159 | 1160 | silvery 1161 | 1162 | 1163 | 1164 | General properties 1165 | 1166 | 1167 | Name, symbol, number 1168 | californium, Cf, 98 1169 | 1170 | 1171 | Pronunciation 1172 | /ˌkælɨˈfɔrniəm/ 1173 | KAL-i-FOR-nee-əm 1174 | 1175 | 1176 | Element category 1177 | actinide 1178 | 1179 | 1180 | Group, period, block 1181 | n/a, 7, f 1182 | 1183 | 1184 | Standard atomic weight 1185 | (251)[1] 1186 | 1187 | 1188 | Electron configuration 1189 | [Rn] 5f10 7s2 [2] 1190 | 2, 8, 18, 32, 28, 8, 2 1191 | 1192 | 1193 | Physical properties 1194 | 1195 | 1196 | Phase 1197 | solid 1198 | 1199 | 1200 | Density (near r.t.) 1201 | 15.1[1] g·cm−3 1202 | 1203 | 1204 | Melting point 1205 | 1173 K, 900[1] °C, 1652 °F 1206 | 1207 | 1208 | Boiling point 1209 | (estimation) 1743[3] K, 1470 °C, 2678 °F 1210 | 1211 | 1212 | Atomic properties 1213 | 1214 | 1215 | Oxidation states 1216 | 2, 3, 4[4] 1217 | 1218 | 1219 | Electronegativity 1220 | 1.3[5] (Pauling scale) 1221 | 1222 | 1223 | Ionization energies 1224 | 1st: 608[6] kJ·mol−1 1225 | 1226 | 1227 | Miscellanea 1228 | 1229 | 1230 | Crystal structure 1231 | simple hexagonal 1232 | 1233 | 1234 | 1235 | 1236 | Mohs hardness 1237 | 3–4[7] 1238 | 1239 | 1240 | CAS registry number 1241 | 7440-71-3[1] 1242 | 1243 | 1244 | History 1245 | 1246 | 1247 | Naming 1248 | after California, where it was discovered 1249 | 1250 | 1251 | Discovery 1252 | Lawrence Berkeley National Laboratory (1950) 1253 | 1254 | 1255 | Most stable isotopes 1256 | 1257 | 1258 | Main article: Isotopes of californium 1259 | 1260 | 1261 | 1262 | 1263 | 1264 | iso 1265 | NA 1266 | half-life 1267 | DM 1268 | DE (MeV) 1269 | DP 1270 | 1271 | 1272 | 248Cf 1273 | syn 1274 | 333.5 d 1275 | α (100%) 1276 | 6.369 1277 | 244Cm 1278 | 1279 | 1280 | SF (2.9×10−3%) 1281 | 0.0029 1282 | – 1283 | 1284 | 1285 | 249Cf 1286 | trace 1287 | 351 y 1288 | α (100%) 1289 | 6.295 1290 | 245Cm 1291 | 1292 | 1293 | SF (5.0×10−7%) 1294 | 4.4×10−7 1295 | – 1296 | 1297 | 1298 | 250Cf 1299 | trace 1300 | 13.08 y 1301 | α (99.92%) 1302 | 6.129 1303 | 246Cm 1304 | 1305 | 1306 | SF (0.08%) 1307 | 0.077 1308 | – 1309 | 1310 | 1311 | 251Cf 1312 | trace 1313 | 898 y 1314 | α 1315 | 6.172 1316 | 247Cm 1317 | 1318 | 1319 | 252Cf 1320 | trace 1321 | 2.645 y 1322 | α (96.91%) 1323 | 6.217 1324 | 248Cm 1325 | 1326 | 1327 | SF (3.09%) 1328 | – 1329 | – 1330 | 1331 | 1332 | 253Cf 1333 | trace 1334 | 17.81 d 1335 | β− (99.69%) 1336 | 0.29 1337 | 253Es 1338 | 1339 | 1340 | α (0.31%) 1341 | 6.126 1342 | 249Cm 1343 | 1344 | 1345 | 254Cf 1346 | syn 1347 | 60.5 d 1348 | SF (99.69%) 1349 | – 1350 | – 1351 | 1352 | 1353 | α (0.31%) 1354 | 5.930 1355 | 250Cm 1356 | 1357 | 1358 | Isotope references:[8][9] 1359 | 1360 | 1361 | 1362 | 1363 | 1364 | 1365 | 1366 | 1367 | view 1368 | talk 1369 | edit 1370 | 1371 | 1372 | · references 1373 | 1374 | 1375 | graphite 1376 | 1377 | Graphite 1378 | 1379 | 1380 | 1381 | Graphite specimen 1382 | 1383 | 1384 | 1385 | General 1386 | 1387 | 1388 | Category 1389 | Native element mineral 1390 | 1391 | 1392 | Formula 1393 | (repeating unit) 1394 | C 1395 | 1396 | 1397 | Strunz classification 1398 | 01.CB.05a 1399 | 1400 | 1401 | Crystal symmetry 1402 | Hexagonal dihexagonal dipyramidal 1403 | H-M symbol: (6/m 2/m 2/m) 1404 | Space group: P 63/mmc 1405 | 1406 | 1407 | Unit cell 1408 | a = 2.461 Å, c = 6.708 Å; Z = 4 1409 | 1410 | 1411 | Identification 1412 | 1413 | 1414 | Color 1415 | Iron-black to steel-gray; deep blue in transmitted light 1416 | 1417 | 1418 | Crystal habit 1419 | Tabular, six-sided foliated masses, granular to compacted masses 1420 | 1421 | 1422 | Crystal system 1423 | Hexagonal 1424 | 1425 | 1426 | Twinning 1427 | Present 1428 | 1429 | 1430 | Cleavage 1431 | Basal – perfect on {0001} 1432 | 1433 | 1434 | Fracture 1435 | Flaky, otherwise rough when not on cleavage 1436 | 1437 | 1438 | Tenacity 1439 | Flexible non-elastic, sectile 1440 | 1441 | 1442 | Mohs scale hardness 1443 | 1–2 1444 | 1445 | 1446 | Luster 1447 | Metallic, earthy 1448 | 1449 | 1450 | Streak 1451 | Black 1452 | 1453 | 1454 | Diaphaneity 1455 | Opaque, transparent only in extremely thin flakes 1456 | 1457 | 1458 | Density 1459 | 2.09–2.23 g/cm3 1460 | 1461 | 1462 | Optical properties 1463 | Uniaxial (–) 1464 | 1465 | 1466 | Pleochroism 1467 | Strong 1468 | 1469 | 1470 | Solubility 1471 | Molten Ni 1472 | 1473 | 1474 | Other characteristics 1475 | strongly anisotropic, electric conductor, greasy feel, readily marks 1476 | 1477 | 1478 | References 1479 | [1][2][3] 1480 | 1481 | 1482 | resonance 1483 | uranium-233 1484 | nuclear weapons 1485 | Listen to this article (info/dl) 1486 | 1487 | 1488 | Sorry, your browser either has JavaScript disabled or does not have any supported player. 1489 | You can download the clip or download a player to play the clip in your browser. 1490 | 1491 | 1492 | 1493 | 1494 | 1495 | 1496 | This audio file was created from a revision of the "Nuclear weapon" article dated 2005-12-01, and does not reflect subsequent edits to the article. (Audio help) 1497 | More spoken articles 1498 | 1499 | thorium cycle 1500 | research reactors 1501 | Standard Model 1502 | magnetic mirrors 1503 | neutron scattering 1504 | neutron radiation 1505 | reactor grade plutonium 1506 | fissionable 1507 | change 1508 | 1509 | Flavour in particle physics 1510 | 1511 | 1512 | Flavour quantum numbers: 1513 | 1514 | Isospin: I or I3 1515 | Charm: C 1516 | Strangeness: S 1517 | Topness: T 1518 | Bottomness: B′ 1519 | 1520 | 1521 | Related quantum numbers: 1522 | 1523 | Baryon number: B 1524 | Lepton number: L 1525 | Weak isospin: T or T3 1526 | Electric charge: Q 1527 | X-charge: X 1528 | 1529 | 1530 | Combinations: 1531 | 1532 | Hypercharge: Y 1533 | 1534 | Y = (B + S + C + B′ + T) 1535 | Y = 2 (Q − I3) 1536 | 1537 | 1538 | Weak hypercharge: YW 1539 | 1540 | YW = 2 (Q − T3) 1541 | X + 2YW = 5 (B − L) 1542 | 1543 | 1544 | 1545 | 1546 | 1547 | Flavour mixing 1548 | 1549 | 1550 | CKM matrix 1551 | PMNS matrix 1552 | Flavour complementarity 1553 | 1554 | 1555 | 1556 | This box: 1557 | 1558 | view 1559 | talk 1560 | edit 1561 | 1562 | 1563 | 1564 | 1565 | 1566 | 1567 | beryllium 1568 | 1569 | Beryllium 1570 | 1571 | 1572 | 4Be 1573 | 1574 | 1575 | 1576 | 1577 | 1578 | 1579 | 1580 | 1581 | 1582 | 1583 | 1584 | 1585 | 1586 | 1587 | 1588 | 1589 | 1590 | 1591 | 1592 | 1593 | 1594 | 1595 | 1596 | 1597 | 1598 | 1599 | 1600 | 1601 | 1602 | 1603 | 1604 | 1605 | 1606 | 1607 | 1608 | 1609 | 1610 | 1611 | 1612 | 1613 | 1614 | 1615 | 1616 | 1617 | 1618 | 1619 | 1620 | 1621 | 1622 | 1623 | 1624 | 1625 | 1626 | 1627 | 1628 | 1629 | 1630 | 1631 | 1632 | 1633 | 1634 | 1635 | 1636 | 1637 | 1638 | 1639 | 1640 | 1641 | 1642 | 1643 | 1644 | 1645 | 1646 | 1647 | 1648 | 1649 | 1650 | 1651 | 1652 | 1653 | 1654 | 1655 | 1656 | 1657 | 1658 | 1659 | 1660 | 1661 | 1662 | 1663 | 1664 | 1665 | 1666 | 1667 | 1668 | 1669 | 1670 | 1671 | 1672 | 1673 | 1674 | 1675 | 1676 | 1677 | 1678 | 1679 | 1680 | 1681 | 1682 | 1683 | 1684 | 1685 | 1686 | 1687 | 1688 | 1689 | 1690 | 1691 | 1692 | 1693 | 1694 | 1695 | 1696 | 1697 | 1698 | 1699 | 1700 | 1701 | 1702 | 1703 | 1704 | 1705 | 1706 | 1707 | 1708 | 1709 | 1710 | 1711 | 1712 | 1713 | 1714 | 1715 | 1716 | 1717 | 1718 | 1719 | 1720 | 1721 | 1722 | 1723 | 1724 | 1725 | 1726 | 1727 | 1728 | 1729 | 1730 | 1731 | 1732 | 1733 | 1734 | 1735 | 1736 | 1737 | 1738 | 1739 | 1740 | 1741 | 1742 | 1743 | 1744 | 1745 | 1746 | 1747 | 1748 | 1749 | 1750 | 1751 | 1752 | 1753 | 1754 | 1755 | 1756 | 1757 | 1758 | 1759 | 1760 | 1761 | 1762 | 1763 | 1764 | 1765 | 1766 | 1767 | 1768 | 1769 | 1770 | 1771 | 1772 | 1773 | 1774 | 1775 | 1776 | 1777 | 1778 | 1779 | 1780 | 1781 | 1782 | 1783 | 1784 | 1785 | 1786 | 1787 | 1788 | 1789 | 1790 | 1791 | 1792 | 1793 | 1794 | 1795 | 1796 | 1797 | 1798 | 1799 | 1800 | 1801 | 1802 | 1803 | 1804 | 1805 | 1806 | 1807 | 1808 | 1809 | 1810 | 1811 | 1812 | 1813 | 1814 | 1815 | 1816 | 1817 | 1818 | 1819 | 1820 | 1821 | 1822 | 1823 | 1824 | 1825 | 1826 | 1827 | 1828 | 1829 | 1830 | 1831 | 1832 | 1833 | 1834 | 1835 | 1836 | 1837 | 1838 | 1839 | 1840 | 1841 | 1842 | 1843 | 1844 | 1845 | 1846 | 1847 | 1848 | 1849 | 1850 | 1851 | 1852 | 1853 | 1854 | 1855 | 1856 | 1857 | 1858 | 1859 | 1860 | 1861 | 1862 | 1863 | 1864 | 1865 | 1866 | 1867 | 1868 | 1869 | 1870 | 1871 | 1872 | 1873 | 1874 | 1875 | 1876 | 1877 | 1878 | 1879 | 1880 | 1881 | 1882 | 1883 | 1884 | 1885 | 1886 | 1887 | 1888 | 1889 | 1890 | 1891 | 1892 | 1893 | 1894 | 1895 | 1896 | 1897 | 1898 | 1899 | 1900 | 1901 | 1902 | 1903 | 1904 | 1905 | 1906 | 1907 | 1908 | 1909 | 1910 | 1911 | 1912 | 1913 | 1914 | 1915 | 1916 | 1917 | 1918 | 1919 | 1920 | 1921 | 1922 | 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929 | 1930 | 1931 | 1932 | 1933 | 1934 | 1935 | 1936 | 1937 | 1938 | 1939 | 1940 | 1941 | 1942 | 1943 | 1944 | 1945 | 1946 | 1947 | 1948 | 1949 | 1950 | 1951 | 1952 | 1953 | 1954 | 1955 | 1956 | 1957 | 1958 | 1959 | - 1960 | ↑ 1961 | Be 1962 | ↓ 1963 | Mg 1964 | 1965 | 1966 | lithium ← beryllium → boron 1967 | 1968 | 1969 | 1970 | 1971 | 1972 | 1973 | 1974 | 1975 | Beryllium in the periodic table 1976 | 1977 | 1978 | Appearance 1979 | 1980 | 1981 | white-gray metallic 1982 | 1983 | 1984 | 1985 | General properties 1986 | 1987 | 1988 | Name, symbol, number 1989 | beryllium, Be, 4 1990 | 1991 | 1992 | Pronunciation 1993 | /bəˈrɪliəm/ bə-RIL-ee-əm 1994 | 1995 | 1996 | Element category 1997 | alkaline earth metal 1998 | 1999 | 2000 | Group, period, block 2001 | 2 (alkaline earth metals), 2, s 2002 | 2003 | 2004 | Standard atomic weight 2005 | 9.0121831(5) 2006 | 2007 | 2008 | Electron configuration 2009 | [He] 2s2 2010 | 2, 2 2011 | 2012 | 2013 | Physical properties 2014 | 2015 | 2016 | Phase 2017 | solid 2018 | 2019 | 2020 | Density (near r.t.) 2021 | 1.85 g·cm−3 2022 | 2023 | 2024 | Liquid density at m.p. 2025 | 1.690 g·cm−3 2026 | 2027 | 2028 | Melting point 2029 | 1560 K, 1287 °C, 2349 °F 2030 | 2031 | 2032 | Boiling point 2033 | 3243 K, 2970 °C, 5338 °F 2034 | 2035 | 2036 | Critical point 2037 | (extrapolated) 2038 | 5205 K, MPa 2039 | 2040 | 2041 | Heat of fusion 2042 | 12.2 kJ·mol−1 2043 | 2044 | 2045 | Heat of vaporization 2046 | 292 kJ·mol−1 2047 | 2048 | 2049 | Molar heat capacity 2050 | 16.443 J·mol−1·K−1 2051 | 2052 | 2053 | Vapor pressure 2054 | 2055 | 2056 | 2057 | 2058 | 2059 | P (Pa) 2060 | 1 2061 | 10 2062 | 100 2063 | 1 k 2064 | 10 k 2065 | 100 k 2066 | 2067 | 2068 | at T (K) 2069 | 1462 2070 | 1608 2071 | 1791 2072 | 2023 2073 | 2327 2074 | 2742 2075 | 2076 | 2077 | 2078 | 2079 | 2080 | Atomic properties 2081 | 2082 | 2083 | Oxidation states 2084 | 2, 1[1] 2085 | (amphoteric oxide) 2086 | 2087 | 2088 | Electronegativity 2089 | 1.57 (Pauling scale) 2090 | 2091 | 2092 | Ionization energies 2093 | (more) 2094 | 1st: 899.5 kJ·mol−1 2095 | 2096 | 2097 | 2nd: 1757.1 kJ·mol−1 2098 | 2099 | 2100 | 3rd: 14848.7 kJ·mol−1 2101 | 2102 | 2103 | Atomic radius 2104 | 112 pm 2105 | 2106 | 2107 | Covalent radius 2108 | 96±3 pm 2109 | 2110 | 2111 | Van der Waals radius 2112 | 153 pm 2113 | 2114 | 2115 | Miscellanea 2116 | 2117 | 2118 | Crystal structure 2119 | hexagonal close-packed 2120 | 2121 | 2122 | 2123 | 2124 | Magnetic ordering 2125 | diamagnetic 2126 | 2127 | 2128 | Electrical resistivity 2129 | (20 °C) 36 nΩ·m 2130 | 2131 | 2132 | Thermal conductivity 2133 | 200 W·m−1·K−1 2134 | 2135 | 2136 | Thermal expansion 2137 | (25 °C) 11.3 µm·m−1·K−1 2138 | 2139 | 2140 | Speed of sound (thin rod) 2141 | (r.t.) 12890[2] m·s−1 2142 | 2143 | 2144 | Young's modulus 2145 | 287 GPa 2146 | 2147 | 2148 | Shear modulus 2149 | 132 GPa 2150 | 2151 | 2152 | Bulk modulus 2153 | 130 GPa 2154 | 2155 | 2156 | Poisson ratio 2157 | 0.032 2158 | 2159 | 2160 | Mohs hardness 2161 | 5.5 2162 | 2163 | 2164 | Vickers hardness 2165 | 1670 MPa 2166 | 2167 | 2168 | Brinell hardness 2169 | 600 MPa 2170 | 2171 | 2172 | CAS registry number 2173 | 7440-41-7 2174 | 2175 | 2176 | History 2177 | 2178 | 2179 | Discovery 2180 | Louis Nicolas Vauquelin (1797) 2181 | 2182 | 2183 | First isolation 2184 | Friedrich Wöhler & Antoine Bussy (1828) 2185 | 2186 | 2187 | Most stable isotopes 2188 | 2189 | 2190 | Main article: Isotopes of beryllium 2191 | 2192 | 2193 | 2194 | 2195 | 2196 | iso 2197 | NA 2198 | half-life 2199 | DM 2200 | DE (MeV) 2201 | DP 2202 | 2203 | 2204 | 7Be 2205 | trace 2206 | 53.12 d 2207 | ε 2208 | 0.862 2209 | 7Li 2210 | 2211 | 2212 | γ 2213 | 0.477 2214 | - 2215 | 2216 | 2217 | 9Be 2218 | 100% 2219 | 9Be is stable with 5 neutrons 2220 | 2221 | 2222 | 10Be 2223 | trace 2224 | 1.36×106 y 2225 | β− 2226 | 0.556 2227 | 10B 2228 | 2229 | 2230 | 2231 | 2232 | 2233 | 2234 | 2235 | 2236 | view 2237 | talk 2238 | edit 2239 | 2240 | 2241 | · references 2242 | 2243 | 2244 | Nuclear reaction 2245 | neutron transport 2246 | cloud chamber 2247 | nuclear fusion reactors 2248 | capture 2249 | moderated 2250 | nuclear force 2251 | e 2252 | 2253 | Elementary charge   (as a unit of charge) 2254 | 2255 | 2256 | Unit system 2257 | Atomic units 2258 | 2259 | 2260 | Unit of 2261 | electric charge 2262 | 2263 | 2264 | Symbol 2265 | e or q  2266 | 2267 | 2268 | Unit conversions 2269 | 2270 | 2271 | 1 e or q in ... 2272 | ... is equal to ... 2273 | 2274 | 2275 |    coulomb 2276 |    1.602176565(35)×10−19[1] 2277 | 2278 | 2279 |    statcoulomb 2280 |    4.80320425(10)×10−10 2281 | 2282 | 2283 |    √(MeV⋅fm) 2284 |    √1.4399764 2285 | 2286 | 2287 | inverse beta decay 2288 | J 2289 | 2290 | 2291 | 2292 | SI multiples for joule (J) 2293 | 2294 | Submultiples 2295 | 2296 | Multiples 2297 | 2298 | 2299 | Value 2300 | Symbol 2301 | Name 2302 | Value 2303 | Symbol 2304 | Name 2305 | 2306 | 2307 | 10−1 J 2308 | dJ 2309 | decijoule 2310 | 101 J 2311 | daJ 2312 | decajoule 2313 | 2314 | 2315 | 10−2 J 2316 | cJ 2317 | centijoule 2318 | 102 J 2319 | hJ 2320 | hectojoule 2321 | 2322 | 2323 | 10−3 J 2324 | mJ 2325 | millijoule 2326 | 103 J 2327 | kJ 2328 | kilojoule 2329 | 2330 | 2331 | 10−6 J 2332 | µJ 2333 | microjoule 2334 | 106 J 2335 | MJ 2336 | megajoule 2337 | 2338 | 2339 | 10−9 J 2340 | nJ 2341 | nanojoule 2342 | 109 J 2343 | GJ 2344 | gigajoule 2345 | 2346 | 2347 | 10−12 J 2348 | pJ 2349 | picojoule 2350 | 1012 J 2351 | TJ 2352 | terajoule 2353 | 2354 | 2355 | 10−15 J 2356 | fJ 2357 | femtojoule 2358 | 1015 J 2359 | PJ 2360 | petajoule 2361 | 2362 | 2363 | 10−18 J 2364 | aJ 2365 | attojoule 2366 | 1018 J 2367 | EJ 2368 | exajoule 2369 | 2370 | 2371 | 10−21 J 2372 | zJ 2373 | zeptojoule 2374 | 1021 J 2375 | ZJ 2376 | zettajoule 2377 | 2378 | 2379 | 10−24 J 2380 | yJ 2381 | yoctojoule 2382 | 1024 J 2383 | YJ 2384 | yottajoule 2385 | 2386 | 2387 | Common multiples are in bold face 2388 | 2389 | 2390 | 2391 | 2392 | 2393 | Cross sections 2394 | Chicago Pile-1 2395 | 2396 | Chicago Pile-1 (CP-1) 2397 | 2398 | 2399 | Reactor concept 2400 | Research reactor (uranium/graphite) 2401 | 2402 | 2403 | Designed and build by 2404 | Metallurgical Laboratory 2405 | 2406 | 2407 | Operational 2408 | 1942 to 1943 2409 | 2410 | 2411 | Status 2412 | Dismantled 2413 | 2414 | 2415 | Main parameters of the reactor core 2416 | 2417 | 2418 | Fuel (fissile material) 2419 | 235U 2420 | 2421 | 2422 | Fuel state 2423 | Solid (pellets) 2424 | 2425 | 2426 | Neutron energy spectrum 2427 | Information missing 2428 | 2429 | 2430 | Primary control method 2431 | Control rods 2432 | 2433 | 2434 | Primary moderator 2435 | Graphite (bricks) 2436 | 2437 | 2438 | Primary coolant 2439 | None 2440 | 2441 | 2442 | Reactor usage 2443 | 2444 | 2445 | Primary use 2446 | Experimental 2447 | 2448 | 2449 | Remarks 2450 | The Chicago Pile-1 (CP-1) was the world's first artificial nuclear reactor. 2451 | 2452 | 2453 | neutron emission 2454 | transmutation 2455 | Frédéric Joliot 2456 | 2457 | Frédéric Joliot-Curie 2458 | 2459 | 2460 | 2461 | 2462 | 2463 | Born 2464 | Jean Frédéric Joliot 2465 | (1900-03-19)19 March 1900 2466 | Paris, France 2467 | 2468 | 2469 | Died 2470 | 14 August 1958(1958-08-14) (aged 58) 2471 | Paris, France 2472 | 2473 | 2474 | Nationality 2475 | France 2476 | 2477 | 2478 | Fields 2479 | Physics 2480 | 2481 | 2482 | Alma mater 2483 | School of Chemistry and Physics of the city of Paris 2484 | 2485 | 2486 | Known for 2487 | Atomic nuclei 2488 | 2489 | 2490 | Notable awards 2491 | Nobel Prize for Chemistry (1935) 2492 | Hughes Medal (1947) 2493 | 2494 | 2495 | Spouse 2496 | Irène Joliot-Curie 2497 | 2498 | 2499 | annihilate 2500 | ionization 2501 | Walther Bothe 2502 | 2503 | Walther Bothe 2504 | 2505 | 2506 | 2507 | Walther Bothe 2508 | 2509 | 2510 | 2511 | Born 2512 | (1891-01-08)8 January 1891 2513 | Oranienburg, German Empire 2514 | 2515 | 2516 | Died 2517 | 8 February 1957(1957-02-08) (aged 66) 2518 | Heidelberg, West Germany 2519 | 2520 | 2521 | Nationality 2522 | Germany 2523 | 2524 | 2525 | Fields 2526 | Physics, mathematics, chemistry 2527 | 2528 | 2529 | Institutions 2530 | University of Berlin 2531 | University of Giessen 2532 | University of Heidelberg 2533 | Max Planck Institute for Medical Research 2534 | 2535 | 2536 | Alma mater 2537 | University of Berlin 2538 | 2539 | 2540 | Doctoral advisor 2541 | Max Planck 2542 | 2543 | 2544 | Doctoral students 2545 | Hans Ritter von Baeyer 2546 | 2547 | 2548 | Known for 2549 | Coincidence circuit 2550 | 2551 | 2552 | Notable awards 2553 | Nobel Prize for Physics (1954) 2554 | Max Planck Medal (1953) 2555 | 2556 | 2557 | reflection 2558 | Faraday effect 2559 | unsolved puzzles in particle physics 2560 | nuclear interaction 2561 | deuterium 2562 | Thermal neutrons 2563 | beta particles 2564 | lithium 2565 | 2566 | NFPA 704 2567 | fire diamond 2568 | 2569 | 2570 | 2571 | 2572 | 2573 | 2574 | 2575 | 2576 | 2577 | 2578 | 2579 | 2580 | 2581 | 2582 | 3 2583 | 2 2584 | W 2585 | 2586 | 2587 | 2588 | 2589 | 2590 | 2591 | Fire diamond hazard sign for lithium metal 2592 | 2593 | 2594 | beyond the Standard Model 2595 | tritium 2596 | cause more fission 2597 | spallation sources 2598 | gamma radiation 2599 | spontaneous fission 2600 | fertile materials 2601 | light water 2602 | neutron generators 2603 | fusion 2604 | boron capture therapy 2605 | nuclear reactions 2606 | neutron activation 2607 | fast neutron reactor 2608 | neutron stars 2609 | fissile 2610 | fission reactors 2611 | thermal reactor 2612 | electron antineutrino 2613 | Electron neutrino 2614 | 2615 | Composition 2616 | Elementary particle 2617 | 2618 | 2619 | Statistics 2620 | Fermionic 2621 | 2622 | 2623 | Generation 2624 | First 2625 | 2626 | 2627 | Interactions 2628 | Weak, Gravity 2629 | 2630 | 2631 | Symbol 2632 | ν 2633 | e 2634 | 2635 | 2636 | Antiparticle 2637 | Electron antineutrino (ν 2638 | e) 2639 | 2640 | 2641 | Theorized 2642 | Wolfgang Pauli (1930) 2643 | 2644 | 2645 | Discovered 2646 | Clyde Cowan, Frederick Reines (1956) 2647 | 2648 | 2649 | Mass 2650 | Small but non-zero. See neutrino mass. 2651 | 2652 | 2653 | Electric charge 2654 | 0 e 2655 | 2656 | 2657 | Color charge 2658 | No 2659 | 2660 | 2661 | Spin 2662 | 1⁄2 2663 | 2664 | 2665 | Weak isospin 2666 | 1⁄2 2667 | 2668 | 2669 | Weak hypercharge 2670 | -1 2671 | Note: the above values apply only to the standard left-handed neutrino. For right-handed neutrinos, see sterile neutrino. 2672 | 2673 | 2674 | neutron capture 2675 | speed of light 2676 | History of measurements of c (in km/s) 2677 | 2678 | 1675 2679 | Rømer and Huygens, moons of Jupiter 2680 | 220000[84][105] 2681 | 2682 | 2683 | 1729 2684 | James Bradley, aberration of light 2685 | 301000[90] 2686 | 2687 | 2688 | 1849 2689 | Hippolyte Fizeau, toothed wheel 2690 | 315000[90] 2691 | 2692 | 2693 | 1862 2694 | Léon Foucault, rotating mirror 2695 | 298000±500[90] 2696 | 2697 | 2698 | 1907 2699 | Rosa and Dorsey, EM constants 2700 | 299710±30[95][96] 2701 | 2702 | 2703 | 1926 2704 | Albert A. Michelson, rotating mirror 2705 | 299796±4[106] 2706 | 2707 | 2708 | 1950 2709 | Essen and Gordon-Smith, cavity resonator 2710 | 299792.5±3.0[98] 2711 | 2712 | 2713 | 1958 2714 | K.D. Froome, radio interferometry 2715 | 299792.50±0.10[102] 2716 | 2717 | 2718 | 1972 2719 | Evenson et al., laser interferometry 2720 | 299792.4562±0.0011[104] 2721 | 2722 | 2723 | 1983 2724 | 17th CGPM, definition of the metre 2725 | 299792.458 (exact)[80] 2726 | 2727 | 2728 | tokamak 2729 | flavour 2730 | 2731 | Flavour in particle physics 2732 | 2733 | 2734 | Flavour quantum numbers: 2735 | 2736 | Isospin: I or I3 2737 | Charm: C 2738 | Strangeness: S 2739 | Topness: T 2740 | Bottomness: B′ 2741 | 2742 | 2743 | Related quantum numbers: 2744 | 2745 | Baryon number: B 2746 | Lepton number: L 2747 | Weak isospin: T or T3 2748 | Electric charge: Q 2749 | X-charge: X 2750 | 2751 | 2752 | Combinations: 2753 | 2754 | Hypercharge: Y 2755 | 2756 | Y = (B + S + C + B′ + T) 2757 | Y = 2 (Q − I3) 2758 | 2759 | 2760 | Weak hypercharge: YW 2761 | 2762 | YW = 2 (Q − T3) 2763 | X + 2YW = 5 (B − L) 2764 | 2765 | 2766 | 2767 | 2768 | 2769 | Flavour mixing 2770 | 2771 | 2772 | CKM matrix 2773 | PMNS matrix 2774 | Flavour complementarity 2775 | 2776 | 2777 | 2778 | This box: 2779 | 2780 | view 2781 | talk 2782 | edit 2783 | 2784 | 2785 | 2786 | 2787 | 2788 | 2789 | USSR 2790 | 2791 | Union of Soviet Socialist Republics 2792 | Other names 2793 | Союз Советских Социалистических Республик 2794 | Soyuz Sovetskikh Sotsialisticheskikh Respublik 2795 | 2796 | 2797 | 2798 | 2799 | 2800 | ← 2801 |   2802 | ← 2803 |   2804 | ← 2805 |   2806 | ← 2807 | 1922–1991[1] 2808 | ↓ 2809 | 2810 | 2811 | 2812 | 2813 | 2814 | 2815 | 2816 | 2817 | 2818 | 2819 | 2820 | 2821 | Flag 2822 | State Emblem 2823 | 2824 | 2825 | 2826 | 2827 | 2828 | Motto 2829 | Пролетарии всех стран, соединяйтесь! 2830 | (Translit.: Proletarii vsekh stran, soyedinyaytes'!) 2831 | English: Workers of the world, unite! 2832 | 2833 | 2834 | Anthem 2835 | "The Internationale" 2836 | (1922–1944) 2837 | 2838 | Sorry, your browser either has JavaScript disabled or does not have any supported player. 2839 | You can download the clip or download a player to play the clip in your browser. 2840 | 2841 | 2842 | "State Anthem of the USSR" 2843 | (1944–1991) 2844 | 2845 | Sorry, your browser either has JavaScript disabled or does not have any supported player. 2846 | You can download the clip or download a player to play the clip in your browser. 2847 | 2848 | 2849 | 2850 | 2851 | 2852 | 2853 | 2854 | 2855 | The Soviet Union after World War II 2856 | 2857 | 2858 | 2859 | Capital 2860 | Moscow 2861 | 2862 | 2863 | Languages 2864 | Russian, many others 2865 | 2866 | 2867 | Religion 2868 | None (state atheism)[2] (see text) 2869 | 2870 | 2871 | Government 2872 | Union, 2873 | Marxist–Leninist single-party state 2874 | 2875 | 2876 | General Secretary 2877 | 2878 | 2879 | 2880 |  -  2881 | 1922-1952 2882 | Joseph Stalin (first) 2883 | 2884 | 2885 |  -  2886 | 1990-1991 2887 | Vladimir Ivashko (last) 2888 | 2889 | 2890 | Head of State 2891 | 2892 | 2893 | 2894 |  -  2895 | 1922–1938 2896 | Mikhail Kalinin (first) 2897 | 2898 | 2899 |  -  2900 | 1988–1991 2901 | Mikhail Gorbachev (last) 2902 | 2903 | 2904 | Head of Government 2905 | 2906 | 2907 | 2908 |  -  2909 | 1922–1924 2910 | Vladimir Lenin (first) 2911 | 2912 | 2913 |  -  2914 | 1991 2915 | Ivan Silayev (last) 2916 | 2917 | 2918 | Legislature 2919 | Supreme Soviet 2920 | 2921 | 2922 |  -  2923 | Upper house 2924 | Soviet of the Union 2925 | 2926 | 2927 |  -  2928 | Lower house 2929 | Soviet of Nationalities 2930 | 2931 | 2932 | Historical era 2933 | Interwar period / World War II / Cold War 2934 | 2935 | 2936 |  -  2937 | Treaty of Creation 2938 | 30 December 1922 2939 | 2940 | 2941 |  -  2942 | Union dissolved 2943 | 26 December 1991[1] 2944 | 2945 | 2946 | Area 2947 | 2948 | 2949 |  -  2950 | 1991 2951 | 22,402,200 km² (8,649,538 sq mi) 2952 | 2953 | 2954 | Population 2955 | 2956 | 2957 |  -  2958 | 1991 est. 2959 | 293,047,571  2960 | 2961 | 2962 |      Density 2963 | 13.1 /km²  (33.9 /sq mi) 2964 | 2965 | 2966 | Currency 2967 | Soviet ruble (руб) (SUR) 2968 | 2969 | 2970 | Internet TLD 2971 | .su1 2972 | 2973 | 2974 | Calling code 2975 | +7 2976 | 2977 | 2978 | 2979 | 2980 | 2981 | 2982 | 2983 | Preceded by 2984 | Succeeded by 2985 | 2986 | 2987 | 2988 | 2989 | 2990 | 2991 | Russian Soviet Federative Socialist Republic 2992 | 2993 | 2994 | 2995 | Transcaucasian Soviet Federative Socialist Republic 2996 | 2997 | 2998 | 2999 | Ukrainian Soviet Socialist Republic 3000 | 3001 | 3002 | 3003 | Byelorussian Soviet Socialist Republic 3004 | 3005 | 3006 | 3007 | 3008 | 3009 | 3010 | Armenia 3011 | 3012 | 3013 | 3014 | Azerbaijan 3015 | 3016 | 3017 | 3018 | Belarus 3019 | 3020 | 3021 | 3022 | Estonia 3023 | 3024 | 3025 | 3026 | Georgia 3027 | 3028 | 3029 | 3030 | Kazakhstan 3031 | 3032 | 3033 | 3034 | Kyrgyzstan 3035 | 3036 | 3037 | 3038 | Latvia 3039 | 3040 | 3041 | 3042 | Lithuania 3043 | 3044 | 3045 | 3046 | Moldova 3047 | 3048 | 3049 | 3050 | Russia 3051 | 3052 | 3053 | 3054 | Tajikistan 3055 | 3056 | 3057 | 3058 | Turkmenistan 3059 | 3060 | 3061 | 3062 | Ukraine 3063 | 3064 | 3065 | 3066 | Uzbekistan 3067 | 3068 | 3069 | 3070 | 3071 | 3072 | 3073 | 3074 | 3075 | 3076 | Notes 3077 | 3078 | ^ Assigned on 19 September 1990, existing onwards. 3079 | 3080 | For details on the succession of states see below. 3081 | 3082 | 3083 | 3084 | down quarks 3085 | Down quark 3086 | 3087 | Composition 3088 | Elementary particle 3089 | 3090 | 3091 | Statistics 3092 | Fermionic 3093 | 3094 | 3095 | Generation 3096 | First 3097 | 3098 | 3099 | Interactions 3100 | Strong, Weak, Electromagnetic force, Gravity 3101 | 3102 | 3103 | Symbol 3104 | d 3105 | 3106 | 3107 | Antiparticle 3108 | Down antiquark (d) 3109 | 3110 | 3111 | Theorized 3112 | Murray Gell-Mann (1964) 3113 | George Zweig (1964) 3114 | 3115 | 3116 | Discovered 3117 | SLAC (1968) 3118 | 3119 | 3120 | Mass 3121 | 4.8+0.5 3122 | −0.3 MeV/c2[1] 3123 | 3124 | 3125 | Decays into 3126 | Stable or Up quark + Electron + Electron antineutrino 3127 | 3128 | 3129 | Electric charge 3130 | −1⁄3 e 3131 | 3132 | 3133 | Color charge 3134 | yes 3135 | 3136 | 3137 | Spin 3138 | 1⁄2 3139 | 3140 | 3141 | Weak isospin 3142 | LH: −1⁄2, RH: 0 3143 | 3144 | 3145 | Weak hypercharge 3146 | LH: 1⁄3, RH: −2⁄3 3147 | 3148 | 3149 | nucleus 3150 | Bruce Cork 3151 | nuclear reactors 3152 | fissioning 3153 | free neutron 3154 | Neutron 3155 | 3156 | 3157 | The quark structure of the neutron. (The color assignment of individual quarks is not important, only that all three colors are present.) 3158 | 3159 | 3160 | 3161 | Classification 3162 | Baryon 3163 | 3164 | 3165 | Composition 3166 | 1 up quark, 2 down quarks 3167 | 3168 | 3169 | Statistics 3170 | Fermionic 3171 | 3172 | 3173 | Interactions 3174 | Gravity, Weak, Strong, Electromagnetic 3175 | 3176 | 3177 | Symbol 3178 | n, n0, N0 3179 | 3180 | 3181 | Antiparticle 3182 | Antineutron 3183 | 3184 | 3185 | Theorized 3186 | Ernest Rutherford[1][2] (1920) 3187 | 3188 | 3189 | Discovered 3190 | James Chadwick[1] (1932) 3191 | 3192 | 3193 | Mass 3194 | 1.674927351(74)×10−27 kg[3] 3195 | 939.565378(21) MeV/c2[3] 3196 | 1.00866491600(43) u[3] 3197 | 3198 | 3199 | Mean lifetime 3200 | 881.5(15) s (free) 3201 | 3202 | 3203 | Electric charge 3204 | 0 e 3205 | 0 C 3206 | 3207 | 3208 | Electric dipole moment 3209 | < 2.9×10−26 e·cm 3210 | 3211 | 3212 | Electric polarizability 3213 | 1.16(15)×10−3 fm3 3214 | 3215 | 3216 | Magnetic moment 3217 | −0.96623647(23)×10−26 J·T−1[3] 3218 | −1.04187563(25)×10−3 μB[3] 3219 | −1.91304272(45) μN[3] 3220 | 3221 | 3222 | Magnetic polarizability 3223 | 3.7(20)×10−4 fm3 3224 | 3225 | 3226 | Spin 3227 | 1⁄2 3228 | 3229 | 3230 | Isospin 3231 | 1⁄2 3232 | 3233 | 3234 | Parity 3235 | +1 3236 | 3237 | 3238 | Condensed 3239 | I(JP) = 1⁄2(1⁄2+) 3240 | 3241 | 3242 | nuclear fission 3243 | boron-10 3244 | 3245 | Boron 3246 | 3247 | 3248 | 5B 3249 | 3250 | 3251 | 3252 | 3253 | 3254 | 3255 | 3256 | 3257 | 3258 | 3259 | 3260 | 3261 | 3262 | 3263 | 3264 | 3265 | 3266 | 3267 | 3268 | 3269 | 3270 | 3271 | 3272 | 3273 | 3274 | 3275 | 3276 | 3277 | 3278 | 3279 | 3280 | 3281 | 3282 | 3283 | 3284 | 3285 | 3286 | 3287 | 3288 | 3289 | 3290 | 3291 | 3292 | 3293 | 3294 | 3295 | 3296 | 3297 | 3298 | 3299 | 3300 | 3301 | 3302 | 3303 | 3304 | 3305 | 3306 | 3307 | 3308 | 3309 | 3310 | 3311 | 3312 | 3313 | 3314 | 3315 | 3316 | 3317 | 3318 | 3319 | 3320 | 3321 | 3322 | 3323 | 3324 | 3325 | 3326 | 3327 | 3328 | 3329 | 3330 | 3331 | 3332 | 3333 | 3334 | 3335 | 3336 | 3337 | 3338 | 3339 | 3340 | 3341 | 3342 | 3343 | 3344 | 3345 | 3346 | 3347 | 3348 | 3349 | 3350 | 3351 | 3352 | 3353 | 3354 | 3355 | 3356 | 3357 | 3358 | 3359 | 3360 | 3361 | 3362 | 3363 | 3364 | 3365 | 3366 | 3367 | 3368 | 3369 | 3370 | 3371 | 3372 | 3373 | 3374 | 3375 | 3376 | 3377 | 3378 | 3379 | 3380 | 3381 | 3382 | 3383 | 3384 | 3385 | 3386 | 3387 | 3388 | 3389 | 3390 | 3391 | 3392 | 3393 | 3394 | 3395 | 3396 | 3397 | 3398 | 3399 | 3400 | 3401 | 3402 | 3403 | 3404 | 3405 | 3406 | 3407 | 3408 | 3409 | 3410 | 3411 | 3412 | 3413 | 3414 | 3415 | 3416 | 3417 | 3418 | 3419 | 3420 | 3421 | 3422 | 3423 | 3424 | 3425 | 3426 | 3427 | 3428 | 3429 | 3430 | 3431 | 3432 | 3433 | 3434 | 3435 | 3436 | 3437 | 3438 | 3439 | 3440 | 3441 | 3442 | 3443 | 3444 | 3445 | 3446 | 3447 | 3448 | 3449 | 3450 | 3451 | 3452 | 3453 | 3454 | 3455 | 3456 | 3457 | 3458 | 3459 | 3460 | 3461 | 3462 | 3463 | 3464 | 3465 | 3466 | 3467 | 3468 | 3469 | 3470 | 3471 | 3472 | 3473 | 3474 | 3475 | 3476 | 3477 | 3478 | 3479 | 3480 | 3481 | 3482 | 3483 | 3484 | 3485 | 3486 | 3487 | 3488 | 3489 | 3490 | 3491 | 3492 | 3493 | 3494 | 3495 | 3496 | 3497 | 3498 | 3499 | 3500 | 3501 | 3502 | 3503 | 3504 | 3505 | 3506 | 3507 | 3508 | 3509 | 3510 | 3511 | 3512 | 3513 | 3514 | 3515 | 3516 | 3517 | 3518 | 3519 | 3520 | 3521 | 3522 | 3523 | 3524 | 3525 | 3526 | 3527 | 3528 | 3529 | 3530 | 3531 | 3532 | 3533 | 3534 | 3535 | 3536 | 3537 | 3538 | 3539 | 3540 | 3541 | 3542 | 3543 | 3544 | 3545 | 3546 | 3547 | 3548 | 3549 | 3550 | 3551 | 3552 | 3553 | 3554 | 3555 | 3556 | 3557 | 3558 | 3559 | 3560 | 3561 | 3562 | 3563 | 3564 | 3565 | 3566 | 3567 | 3568 | 3569 | 3570 | 3571 | 3572 | 3573 | 3574 | 3575 | 3576 | 3577 | 3578 | 3579 | 3580 | 3581 | 3582 | 3583 | 3584 | 3585 | 3586 | 3587 | 3588 | 3589 | 3590 | 3591 | 3592 | 3593 | 3594 | 3595 | 3596 | 3597 | 3598 | 3599 | 3600 | 3601 | 3602 | 3603 | 3604 | 3605 | 3606 | 3607 | 3608 | 3609 | 3610 | 3611 | 3612 | 3613 | 3614 | 3615 | 3616 | 3617 | 3618 | 3619 | 3620 | 3621 | 3622 | 3623 | 3624 | 3625 | 3626 | 3627 | 3628 | 3629 | 3630 | 3631 | 3632 | 3633 | 3634 | 3635 | - 3636 | ↑ 3637 | B 3638 | ↓ 3639 | Al 3640 | 3641 | 3642 | beryllium ← boron → carbon 3643 | 3644 | 3645 | 3646 | 3647 | 3648 | 3649 | 3650 | 3651 | Boron in the periodic table 3652 | 3653 | 3654 | Appearance 3655 | 3656 | 3657 | black-brown 3658 | 3659 | Boron, shown here in the form of its β-rhombohedral phase (its most thermodynamically stable allotrope)[1] 3660 | 3661 | 3662 | General properties 3663 | 3664 | 3665 | Name, symbol, number 3666 | boron, B, 5 3667 | 3668 | 3669 | Pronunciation 3670 | /ˈbɔərɒn/ 3671 | 3672 | 3673 | Element category 3674 | metalloid 3675 | 3676 | 3677 | Group, period, block 3678 | 13, 2, p 3679 | 3680 | 3681 | Standard atomic weight 3682 | 10.81(1) 3683 | 3684 | 3685 | Electron configuration 3686 | [He] 2s2 2p1 3687 | 2, 3 3688 | 3689 | 3690 | Physical properties 3691 | 3692 | 3693 | Phase 3694 | solid 3695 | 3696 | 3697 | Liquid density at m.p. 3698 | 2.08 g·cm−3 3699 | 3700 | 3701 | Melting point 3702 | 2349 K, 2076 °C, 3769 °F 3703 | 3704 | 3705 | Boiling point 3706 | 4200 K, 3927 °C, 7101 °F 3707 | 3708 | 3709 | Heat of fusion 3710 | 50.2 kJ·mol−1 3711 | 3712 | 3713 | Heat of vaporization 3714 | 508 kJ·mol−1 3715 | 3716 | 3717 | Molar heat capacity 3718 | 11.087 J·mol−1·K−1 3719 | 3720 | 3721 | Vapor pressure 3722 | 3723 | 3724 | 3725 | 3726 | 3727 | P (Pa) 3728 | 1 3729 | 10 3730 | 100 3731 | 1 k 3732 | 10 k 3733 | 100 k 3734 | 3735 | 3736 | at T (K) 3737 | 2348 3738 | 2562 3739 | 2822 3740 | 3141 3741 | 3545 3742 | 4072 3743 | 3744 | 3745 | 3746 | 3747 | 3748 | Atomic properties 3749 | 3750 | 3751 | Oxidation states 3752 | 3, 2, 1[2] 3753 | (mildly acidic oxide) 3754 | 3755 | 3756 | Electronegativity 3757 | 2.04 (Pauling scale) 3758 | 3759 | 3760 | Ionization energies 3761 | (more) 3762 | 1st: 800.6 kJ·mol−1 3763 | 3764 | 3765 | 2nd: 2427.1 kJ·mol−1 3766 | 3767 | 3768 | 3rd: 3659.7 kJ·mol−1 3769 | 3770 | 3771 | Atomic radius 3772 | 90 pm 3773 | 3774 | 3775 | Covalent radius 3776 | 84±3 pm 3777 | 3778 | 3779 | Van der Waals radius 3780 | 192 pm 3781 | 3782 | 3783 | Miscellanea 3784 | 3785 | 3786 | Crystal structure 3787 | rhombohedral 3788 | 3789 | 3790 | 3791 | 3792 | Magnetic ordering 3793 | diamagnetic[3] 3794 | 3795 | 3796 | Electrical resistivity 3797 | (20 °C) ~106 Ω·m 3798 | 3799 | 3800 | Thermal conductivity 3801 | 27.4 W·m−1·K−1 3802 | 3803 | 3804 | Thermal expansion 3805 | (25 °C) (β form) 5–7[4] µm·m−1·K−1 3806 | 3807 | 3808 | Speed of sound (thin rod) 3809 | (20 °C) 16,200 m·s−1 3810 | 3811 | 3812 | Mohs hardness 3813 | ~9.5 3814 | 3815 | 3816 | CAS registry number 3817 | 7440-42-8 3818 | 3819 | 3820 | History 3821 | 3822 | 3823 | Discovery 3824 | Joseph Louis Gay-Lussac and Louis Jacques Thénard[5] (30 June 1808) 3825 | 3826 | 3827 | First isolation 3828 | Humphry Davy[6] (9 July 1808) 3829 | 3830 | 3831 | Most stable isotopes 3832 | 3833 | 3834 | Main article: Isotopes of boron 3835 | 3836 | 3837 | 3838 | 3839 | 3840 | iso 3841 | NA 3842 | half-life 3843 | DM 3844 | DE (MeV) 3845 | DP 3846 | 3847 | 3848 | 10B 3849 | 19.9(7)% 3850 | 10B is stable with 5 neutrons[7] 3851 | 3852 | 3853 | 11B 3854 | 80.1(7)% 3855 | 11B is stable with 6 neutrons[7] 3856 | 3857 | 3858 | 10B content may be as low as 19.1% and as high as 20.3% in natural samples. 11B is the remainder in such cases.[8] 3859 | 3860 | 3861 | 3862 | 3863 | 3864 | 3865 | 3866 | 3867 | view 3868 | talk 3869 | edit 3870 | 3871 | 3872 | · references 3873 | 3874 | 3875 | antielectron 3876 | Positron (antielectron) 3877 | 3878 | 3879 | Cloud chamber photograph by C. D. Anderson of the first positron ever identified. A 6 mm lead plate separates the upper half of the chamber from the lower half. The positron must have come from below since the upper track is bent more strongly in the magnetic field indicating a lower energy. 3880 | 3881 | 3882 | 3883 | Composition 3884 | Elementary particle 3885 | 3886 | 3887 | Statistics 3888 | Fermionic 3889 | 3890 | 3891 | Generation 3892 | First 3893 | 3894 | 3895 | Interactions 3896 | Gravity, Electromagnetic, Weak 3897 | 3898 | 3899 | Symbol 3900 | β+, e+ 3901 | 3902 | 3903 | Antiparticle 3904 | Electron 3905 | 3906 | 3907 | Theorized 3908 | Paul Dirac (1928) 3909 | 3910 | 3911 | Discovered 3912 | Carl D. Anderson (1932) 3913 | 3914 | 3915 | Mass 3916 | 3917 | 9.10938291(40)×10−31 kg[1] 3918 | 5.4857990946(22)×10−4 u[1] 3919 | [1822.8884845(14)]−1 u[note 1] 3920 | 0.510998928(11) MeV/c2[1] 3921 | 3922 | 3923 | Electric charge 3924 | +1 e 3925 | 1.602176565(35)×10−19 C[1] 3926 | 3927 | 3928 | Spin 3929 | 1⁄2 3930 | 3931 | 3932 | alpha decay 3933 | Greek 3934 | 3935 | Greek 3936 | 3937 | 3938 | ελληνικά 3939 | 3940 | 3941 | Pronunciation 3942 | [eliniˈka] 3943 | 3944 | 3945 | Region 3946 | Eastern Mediterranean 3947 | 3948 | 3949 | 3950 | Native speakers 3951 | 3952 | 12 million  (2007)[1] 3953 | 13 million (L1 plus L2 speakers) (2012)[2] 3954 | 3955 | 3956 | 3957 | Language family 3958 | 3959 | 3960 | Indo-European 3961 | 3962 | Hellenic 3963 | 3964 | Greek 3965 | 3966 | 3967 | 3968 | 3969 | 3970 | 3971 | 3972 | Dialects 3973 | 3974 | Ancient dialects 3975 | Modern dialects 3976 | 3977 | 3978 | 3979 | 3980 | Writing system 3981 | 3982 | 3983 | 3984 | 3985 | Greek alphabet 3986 | Greek Braille 3987 | 3988 | 3989 | 3990 | 3991 | 3992 | Official status 3993 | 3994 | 3995 | 3996 | Official language in 3997 | 3998 | 3999 | 4000 | 4001 |  Greece 4002 |  Cyprus 4003 |  European Union 4004 | 4005 | 4006 | 4007 | 4008 | 4009 | 4010 | Recognised minority language in 4011 | 4012 | 4013 | 4014 | 4015 |  Albania[3][4] 4016 |  Armenia[5] 4017 |  Hungary[6] 4018 |  Italy[7] 4019 |  Romania[5] 4020 |  Turkey[8] 4021 |  Ukraine[5] 4022 | 4023 | 4024 | 4025 | 4026 | 4027 | Language codes 4028 | 4029 | 4030 | ISO 639-1 4031 | el 4032 | 4033 | 4034 | ISO 639-3 4035 | Variously: 4036 | grc – Ancient Greek 4037 | cpg – Cappadocian Greek 4038 | ell – Modern Greek 4039 | gmy – Mycenaean Greek 4040 | pnt – Pontic 4041 | tsd – Tsakonian 4042 | yej – Yevanic 4043 | 4044 | 4045 | Glottolog 4046 | gree1276[9] 4047 | 4048 | 4049 | Linguasphere 4050 | 4051 | 4052 | 4053 | 56-AAA-a 4054 | 56-AAA-aa to -am (varieties) 4055 | 4056 | 4057 | 4058 | 4059 | 4060 | This article contains IPA phonetic symbols. Without proper rendering support, you may see question marks, boxes, or other symbols instead of Unicode characters. 4061 | 4062 | 4063 | beta decay 4064 | cross section 4065 | X-rays 4066 | cross sections 4067 | nucleons 4068 | Irène Joliot-Curie 4069 | 4070 | Irène Joliot-Curie 4071 | 4072 | 4073 | 4074 | 4075 | 4076 | Born 4077 | (1897-09-12)12 September 1897 4078 | Paris, France 4079 | 4080 | 4081 | Died 4082 | 17 March 1956(1956-03-17) (aged 58) 4083 | Paris, France 4084 | 4085 | 4086 | Residence 4087 | Paris, France 4088 | 4089 | 4090 | Citizenship 4091 | French 4092 | 4093 | 4094 | Nationality 4095 | French, of French and Polish descent 4096 | 4097 | 4098 | Fields 4099 | Chemistry 4100 | 4101 | 4102 | Alma mater 4103 | Sorbonne 4104 | 4105 | 4106 | Doctoral advisor 4107 | Paul Langevin 4108 | 4109 | 4110 | Doctoral students 4111 | her daughters (see below) 4112 | 4113 | 4114 | Notable awards 4115 | Nobel Prize for Chemistry (1935) 4116 | 4117 | 4118 | Spouse 4119 | Frédéric Joliot-Curie (1900–1958) 4120 | 4121 | 4122 | Children 4123 | Hélène Langevin-Joliot (b. 1927) 4124 | Pierre Joliot (b. 1932) 4125 | 4126 | 4127 | photons 4128 | Photon 4129 | 4130 | 4131 | Photons emitted in a coherent beam from a laser 4132 | 4133 | 4134 | 4135 | Composition 4136 | Elementary particle 4137 | 4138 | 4139 | Statistics 4140 | Bosonic 4141 | 4142 | 4143 | Interactions 4144 | Electromagnetic 4145 | 4146 | 4147 | Symbol 4148 | γ, hν, or ħω 4149 | 4150 | 4151 | Theorized 4152 | Albert Einstein 4153 | 4154 | 4155 | Mass 4156 | 0 4157 | <1×10−18 eV/c2[1] 4158 | 4159 | 4160 | Mean lifetime 4161 | Stable[1] 4162 | 4163 | 4164 | Electric charge 4165 | 0 4166 | <1×10−35 e[1] 4167 | 4168 | 4169 | Spin 4170 | 1 4171 | 4172 | 4173 | Parity 4174 | −1[1] 4175 | 4176 | 4177 | C parity 4178 | −1[1] 4179 | 4180 | 4181 | Condensed 4182 | I(JPC)=0,1(1−−)[1] 4183 | 4184 | 4185 | nuclear reactor 4186 | fast breeder 4187 | fusion reaction 4188 | carbon-14 4189 | Planck constant 4190 | spallation 4191 | chemical element 4192 | 4193 | 4194 | 4195 | 4196 | 4197 | 4198 | 4199 | 4200 | 4201 | 4202 | 4203 | 4204 | 4205 | Top: The periodic table of the chemical elements. Below: Examples of certain chemical elements. From left to right: hydrogen, barium, copper, uranium, bromine, and helium. 4206 | 4207 | 4208 | atoms 4209 | mean lifetime 4210 | neutronium 4211 | neutron number 4212 | radioisotope 4213 | baryon number 4214 | 4215 | Flavour in particle physics 4216 | 4217 | 4218 | Flavour quantum numbers: 4219 | 4220 | Isospin: I or I3 4221 | Charm: C 4222 | Strangeness: S 4223 | Topness: T 4224 | Bottomness: B′ 4225 | 4226 | 4227 | Related quantum numbers: 4228 | 4229 | Baryon number: B 4230 | Lepton number: L 4231 | Weak isospin: T or T3 4232 | Electric charge: Q 4233 | X-charge: X 4234 | 4235 | 4236 | Combinations: 4237 | 4238 | Hypercharge: Y 4239 | 4240 | Y = (B + S + C + B′ + T) 4241 | Y = 2 (Q − I3) 4242 | 4243 | 4244 | Weak hypercharge: YW 4245 | 4246 | YW = 2 (Q − T3) 4247 | X + 2YW = 5 (B − L) 4248 | 4249 | 4250 | 4251 | 4252 | 4253 | Flavour mixing 4254 | 4255 | 4256 | CKM matrix 4257 | PMNS matrix 4258 | Flavour complementarity 4259 | 4260 | 4261 | 4262 | This box: 4263 | 4264 | view 4265 | talk 4266 | edit 4267 | 4268 | 4269 | 4270 | 4271 | 4272 | 4273 | W boson 4274 | W± and Z0 Bosons 4275 | 4276 | Composition 4277 | Elementary particle 4278 | 4279 | 4280 | Statistics 4281 | Bosonic 4282 | 4283 | 4284 | Interactions 4285 | Weak interaction 4286 | 4287 | 4288 | Theorized 4289 | Glashow, Weinberg, Salam (1968) 4290 | 4291 | 4292 | Discovered 4293 | UA1 and UA2 collaborations, CERN, 1983 4294 | 4295 | 4296 | Mass 4297 | W: 80.385±0.015 GeV/c2[1] 4298 | Z: 91.1876±0.0021 GeV/c2[1] 4299 | 4300 | 4301 | Decay width 4302 | W: 2.085±0.042 GeV/c2[1] 4303 | Z: 2.4952±0.0023 GeV/c2 [1] 4304 | 4305 | 4306 | Electric charge 4307 | W: ±1 e 4308 | Z: 0 e 4309 | 4310 | 4311 | Spin 4312 | 1 4313 | 4314 | 4315 | neutrino 4316 | Neutrino/Antineutrino 4317 | 4318 | 4319 | The first use of a hydrogen bubble chamber to detect neutrinos, on November 13, 1970. A neutrino hit a proton in a hydrogen atom. The collision occurred at the point where three tracks emanate on the right of the photograph. 4320 | 4321 | 4322 | 4323 | Composition 4324 | Elementary particle 4325 | 4326 | 4327 | Statistics 4328 | Fermionic 4329 | 4330 | 4331 | Generation 4332 | First, second and third 4333 | 4334 | 4335 | Interactions 4336 | Weak interaction and gravitation 4337 | 4338 | 4339 | Symbol 4340 | ν 4341 | e, ν 4342 | μ, ν 4343 | τ, ν 4344 | e, ν 4345 | μ, ν 4346 | τ 4347 | 4348 | 4349 | Antiparticle 4350 | Antineutrinos are possibly identical to the neutrino (see Majorana fermion). 4351 | 4352 | 4353 | Theorized 4354 | 4355 | ν 4356 | e (Electron neutrino): Wolfgang Pauli (1930) 4357 | ν 4358 | μ (Muon neutrino): Late 1940s 4359 | ν 4360 | τ (Tau neutrino): Mid 1970s 4361 | 4362 | 4363 | Discovered 4364 | ν 4365 | e: Clyde Cowan, Frederick Reines (1956) 4366 | ν 4367 | μ: Leon Lederman, Melvin Schwartz and Jack Steinberger (1962) 4368 | ν 4369 | τ: DONUT collaboration (2000) 4370 | 4371 | 4372 | Types 4373 | 3 – electron neutrino, muon neutrino and tau neutrino 4374 | 4375 | 4376 | Mass 4377 | 0.320 ± 0.081 eV (sum of 3 flavors)[1][2][3] 4378 | 4379 | 4380 | Electric charge 4381 | 0 e 4382 | 4383 | 4384 | Spin 4385 | 1⁄2 4386 | 4387 | 4388 | Weak hypercharge 4389 | −1 4390 | 4391 | 4392 | B − L 4393 | −1 4394 | 4395 | 4396 | X 4397 | −3 4398 | 4399 | 4400 | Cold, thermal and hot 4401 | radiation 4402 | unstable 4403 | nuclear transmutations 4404 | Latin 4405 | 4406 | Latin 4407 | 4408 | 4409 | Lingua latina 4410 | 4411 | 4412 | 4413 | Latin inscription in the Colosseum 4414 | 4415 | 4416 | 4417 | Pronunciation 4418 | [laˈtiːna] 4419 | 4420 | 4421 | Native to 4422 | Latium, Roman Kingdom, Roman Republic, Roman Empire, Medieval and Early modern Europe, Armenian Kingdom of Cilicia (as lingua franca), Vatican City 4423 | 4424 | 4425 | Ethnicity 4426 | Latins 4427 | 4428 | 4429 | Era 4430 | Vulgar Latin developed into Romance languages, 6th to 9th centuries; the formal language continued as the scholarly lingua franca of Catholic countries medieval Europe and as the liturgical language of the Roman Catholic Church. 4431 | 4432 | 4433 | 4434 | Language family 4435 | 4436 | 4437 | Indo-European 4438 | 4439 | Italic 4440 | 4441 | Latino-Faliscan 4442 | 4443 | Latin 4444 | 4445 | 4446 | 4447 | 4448 | 4449 | 4450 | 4451 | 4452 | 4453 | 4454 | Writing system 4455 | 4456 | Latin alphabet  4457 | 4458 | 4459 | Official status 4460 | 4461 | 4462 | 4463 | Official language in 4464 | 4465 |  Sovereign Military Order of Malta   Vatican City 4466 | 4467 | 4468 | Regulated by 4469 | In antiquity, Roman schools of grammar and rhetoric.[1] Today, the Pontifical Academy for Latin. 4470 | 4471 | 4472 | Language codes 4473 | 4474 | 4475 | ISO 639-1 4476 | la 4477 | 4478 | 4479 | ISO 639-2 4480 | lat 4481 | 4482 | 4483 | ISO 639-3 4484 | lat 4485 | 4486 | 4487 | Glottolog 4488 | lati1261[2] 4489 | 4490 | 4491 | Linguasphere 4492 | 51-AAB-a 4493 | 4494 | 4495 | 4496 | Greatest extent of the Roman Empire, showing the area governed by Latin speakers. Many languages other than Latin, most notably Greek, were spoken within the empire. 4497 | 4498 | 4499 | 4500 | 4501 | Range of the Romance languages, the modern descendants of Latin, in Europe 4502 | 4503 | 4504 | 4505 | This article contains IPA phonetic symbols. Without proper rendering support, you may see question marks, boxes, or other symbols instead of Unicode characters. 4506 | 4507 | 4508 | half-life 4509 | particle 4510 | gamma rays 4511 | lithium-7 4512 | mode 4513 | hadron 4514 | neutron moderator 4515 | polonium 4516 | 4517 | Polonium 4518 | 4519 | 4520 | 84Po 4521 | 4522 | 4523 | 4524 | 4525 | 4526 | 4527 | 4528 | 4529 | 4530 | 4531 | 4532 | 4533 | 4534 | 4535 | 4536 | 4537 | 4538 | 4539 | 4540 | 4541 | 4542 | 4543 | 4544 | 4545 | 4546 | 4547 | 4548 | 4549 | 4550 | 4551 | 4552 | 4553 | 4554 | 4555 | 4556 | 4557 | 4558 | 4559 | 4560 | 4561 | 4562 | 4563 | 4564 | 4565 | 4566 | 4567 | 4568 | 4569 | 4570 | 4571 | 4572 | 4573 | 4574 | 4575 | 4576 | 4577 | 4578 | 4579 | 4580 | 4581 | 4582 | 4583 | 4584 | 4585 | 4586 | 4587 | 4588 | 4589 | 4590 | 4591 | 4592 | 4593 | 4594 | 4595 | 4596 | 4597 | 4598 | 4599 | 4600 | 4601 | 4602 | 4603 | 4604 | 4605 | 4606 | 4607 | 4608 | 4609 | 4610 | 4611 | 4612 | 4613 | 4614 | 4615 | 4616 | 4617 | 4618 | 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4905 | 4906 | 4907 | Te 4908 | ↑ 4909 | Po 4910 | ↓ 4911 | Lv 4912 | 4913 | 4914 | bismuth ← polonium → astatine 4915 | 4916 | 4917 | 4918 | 4919 | 4920 | 4921 | 4922 | 4923 | Polonium in the periodic table 4924 | 4925 | 4926 | Appearance 4927 | 4928 | 4929 | silvery 4930 | 4931 | 4932 | 4933 | General properties 4934 | 4935 | 4936 | Name, symbol, number 4937 | polonium, Po, 84 4938 | 4939 | 4940 | Pronunciation 4941 | /pɵˈloʊniəm/ po-LOH-nee-əm 4942 | 4943 | 4944 | Element category 4945 | other metal 4946 | other metal status is disputed (see article text) 4947 | 4948 | 4949 | Group, period, block 4950 | 16 (chalcogens), 6, p 4951 | 4952 | 4953 | Standard atomic weight 4954 | (209) 4955 | 4956 | 4957 | Electron configuration 4958 | [Xe] 6s2 4f14 5d10 6p4 4959 | 2, 8, 18, 32, 18, 6 4960 | 4961 | 4962 | Physical properties 4963 | 4964 | 4965 | Phase 4966 | solid 4967 | 4968 | 4969 | Density (near r.t.) 4970 | (alpha) 9.196 g·cm−3 4971 | 4972 | 4973 | Density (near r.t.) 4974 | (beta) 9.398 g·cm−3 4975 | 4976 | 4977 | Melting point 4978 | 527 K, 254 °C, 489 °F 4979 | 4980 | 4981 | Boiling point 4982 | 1235 K, 962 °C, 1764 °F 4983 | 4984 | 4985 | Heat of fusion 4986 | ca. 13 kJ·mol−1 4987 | 4988 | 4989 | Heat of vaporization 4990 | 102.91 kJ·mol−1 4991 | 4992 | 4993 | Molar heat capacity 4994 | 26.4 J·mol−1·K−1 4995 | 4996 | 4997 | Vapor pressure 4998 | 4999 | 5000 | 5001 | 5002 | 5003 | P (Pa) 5004 | 1 5005 | 10 5006 | 100 5007 | 1 k 5008 | 10 k 5009 | 100 k 5010 | 5011 | 5012 | at T (K) 5013 |   5014 |   5015 |   5016 | (846) 5017 | 1003 5018 | 1236 5019 | 5020 | 5021 | 5022 | 5023 | 5024 | Atomic properties 5025 | 5026 | 5027 | Oxidation states 5028 | 6, 5,[1] 4, 2, −2 5029 | (amphoteric oxide) 5030 | 5031 | 5032 | Electronegativity 5033 | 2.0 (Pauling scale) 5034 | 5035 | 5036 | Ionization energies 5037 | 1st: 812.1 kJ·mol−1 5038 | 5039 | 5040 | Atomic radius 5041 | 168 pm 5042 | 5043 | 5044 | Covalent radius 5045 | 140±4 pm 5046 | 5047 | 5048 | Van der Waals radius 5049 | 197 pm 5050 | 5051 | 5052 | Miscellanea 5053 | 5054 | 5055 | Crystal structure 5056 | cubic 5057 | 5058 | 5059 | 5060 | 5061 | Magnetic ordering 5062 | nonmagnetic 5063 | 5064 | 5065 | Electrical resistivity 5066 | (0 °C) (α) 0.40 µΩ·m 5067 | 5068 | 5069 | Thermal conductivity 5070 |  ? 20 W·m−1·K−1 5071 | 5072 | 5073 | Thermal expansion 5074 | (25 °C) 23.5 µm·m−1·K−1 5075 | 5076 | 5077 | CAS registry number 5078 | 7440-08-6 5079 | 5080 | 5081 | History 5082 | 5083 | 5084 | Discovery 5085 | Pierre Curie and Marie Curie (1898) 5086 | 5087 | 5088 | First isolation 5089 | Willy Marckwald (1902) 5090 | 5091 | 5092 | Most stable isotopes 5093 | 5094 | 5095 | Main article: Isotopes of polonium 5096 | 5097 | 5098 | 5099 | 5100 | 5101 | iso 5102 | NA 5103 | half-life 5104 | DM 5105 | DE (MeV) 5106 | DP 5107 | 5108 | 5109 | 208Po 5110 | syn 5111 | 2.898 y 5112 | α 5113 | 5.215 5114 | 204Pb 5115 | 5116 | 5117 | β+ 5118 | 1.401 5119 | 208Bi 5120 | 5121 | 5122 | 209Po 5123 | syn 5124 | 103 y 5125 | α 5126 | 4.979 5127 | 205Pb 5128 | 5129 | 5130 | β+ 5131 | 1.893 5132 | 209Bi 5133 | 5134 | 5135 | 210Po 5136 | trace 5137 | 138.376 d 5138 | α 5139 | 5.307 5140 | 206Pb 5141 | 5142 | 5143 | 5144 | 5145 | 5146 | 5147 | 5148 | 5149 | view 5150 | talk 5151 | edit 5152 | 5153 | 5154 | · references 5155 | 5156 | 5157 | neutron activation analysis 5158 | electron 5159 | Electron 5160 | 5161 | 5162 | Experiments with a Crookes tube first demonstrated the particle nature of electrons. In this illustration, the profile of the Maltese-cross-shaped target is projected against the tube face at right by a beam of electrons.[1] 5163 | 5164 | 5165 | 5166 | Composition 5167 | Elementary particle[2] 5168 | 5169 | 5170 | Statistics 5171 | Fermionic 5172 | 5173 | 5174 | Generation 5175 | First 5176 | 5177 | 5178 | Interactions 5179 | Gravity, Electromagnetic, Weak 5180 | 5181 | 5182 | Symbol 5183 | e−, β− 5184 | 5185 | 5186 | Antiparticle 5187 | Positron (also called antielectron) 5188 | 5189 | 5190 | Theorized 5191 | Richard Laming (1838–1851),[3] 5192 | G. Johnstone Stoney (1874) and others.[4][5] 5193 | 5194 | 5195 | Discovered 5196 | J. J. Thomson (1897)[6] 5197 | 5198 | 5199 | Mass 5200 | 9.10938291(40)×10−31 kg[7] 5201 | 5.4857990946(22)×10−4 u[7] 5202 | [1822.8884845(14)]−1 u[note 1] 5203 | 0.510998928(11) MeV/c2[7] 5204 | 5205 | 5206 | Electric charge 5207 | −1 e[note 2] 5208 | −1.602176565(35)×10−19 C[7] 5209 | −4.80320451(10)×10−10 [[esu]] 5210 | 5211 | 5212 | Magnetic moment 5213 | −1.00115965218076(27) μB[7] 5214 | 5215 | 5216 | Spin 5217 | 1⁄2 5218 | 5219 | 5220 | quantum mechanics 5221 | quarks 5222 | Quark 5223 | 5224 | 5225 | A proton, composed of two up quarks and one down quark. (The color assignment of individual quarks is not important, only that all three colors be present.) 5226 | 5227 | 5228 | 5229 | Composition 5230 | Elementary particle 5231 | 5232 | 5233 | Statistics 5234 | Fermionic 5235 | 5236 | 5237 | Generation 5238 | 1st, 2nd, 3rd 5239 | 5240 | 5241 | Interactions 5242 | Electromagnetism, Gravitation, Strong, Weak 5243 | 5244 | 5245 | Symbol 5246 | q 5247 | 5248 | 5249 | Antiparticle 5250 | Antiquark (q) 5251 | 5252 | 5253 | Theorized 5254 | Murray Gell-Mann (1964) 5255 | George Zweig (1964) 5256 | 5257 | 5258 | Discovered 5259 | SLAC (~1968) 5260 | 5261 | 5262 | Types 5263 | 6 (up, down, strange, charm, bottom, and top) 5264 | 5265 | 5266 | Electric charge 5267 | +2⁄3 e, −1⁄3 e 5268 | 5269 | 5270 | Color charge 5271 | Yes 5272 | 5273 | 5274 | Spin 5275 | 1⁄2 5276 | 5277 | 5278 | Baryon number 5279 | 1⁄3 5280 | 5281 | 5282 | uranium-235 5283 | nuclear chain reaction 5284 | bremsstrahlung 5285 | hydrogen atom 5286 | molecules 5287 | antimony-124 5288 | actinide 5289 | carbon-12 5290 | James Chadwick 5291 | 5292 | Sir James Chadwick 5293 | 5294 | 5295 | 5296 | 5297 | 5298 | Born 5299 | (1891-10-20)20 October 1891 5300 | Bollington, Cheshire, England 5301 | 5302 | 5303 | Died 5304 | 24 July 1974(1974-07-24) (aged 82) 5305 | Cambridge, England 5306 | 5307 | 5308 | Citizenship 5309 | United Kingdom 5310 | 5311 | 5312 | Fields 5313 | Physics 5314 | 5315 | 5316 | Institutions 5317 | 5318 | 5319 | 5320 | Physikalisch-Technische Reichsanstalt 5321 | University of Liverpool 5322 | Gonville and Caius College, Cambridge 5323 | Manhattan Project 5324 | 5325 | 5326 | 5327 | 5328 | 5329 | Alma mater 5330 | 5331 | 5332 | 5333 | University of Manchester 5334 | University of Cambridge 5335 | 5336 | 5337 | 5338 | 5339 | 5340 | Doctoral advisor 5341 | Ernest Rutherford 5342 | 5343 | 5344 | Doctoral students 5345 | 5346 | 5347 | 5348 | Maurice Goldhaber 5349 | Ernest C. Pollard 5350 | Charles Drummond Ellis 5351 | 5352 | 5353 | 5354 | 5355 | 5356 | Known for 5357 | 5358 | 5359 | 5360 | Discovery of the neutron 5361 | Maud Committee Report 5362 | Manhattan Project 5363 | 5364 | 5365 | 5366 | 5367 | 5368 | Notable awards 5369 | 5370 | 5371 | 5372 | Fellow of the Royal Society (1927)[1] 5373 | Hughes Medal (1932) 5374 | Mackenzie-Davidson Medal (1932) 5375 | Nobel Prize in Physics (1935) 5376 | Knight Bachelor (1945) 5377 | Melchett Medal (1946) 5378 | Copley Medal (1950) 5379 | Faraday Medal (1950) 5380 | Franklin Medal (1951) 5381 | Guthrie Medal and Prize (1967) 5382 | Companion of Honour (1970) 5383 | 5384 | 5385 | 5386 | 5387 | 5388 | weak interaction 5389 | velocity selection 5390 | electric charge 5391 | 5392 | Flavour in particle physics 5393 | 5394 | 5395 | Flavour quantum numbers: 5396 | 5397 | Isospin: I or I3 5398 | Charm: C 5399 | Strangeness: S 5400 | Topness: T 5401 | Bottomness: B′ 5402 | 5403 | 5404 | Related quantum numbers: 5405 | 5406 | Baryon number: B 5407 | Lepton number: L 5408 | Weak isospin: T or T3 5409 | Electric charge: Q 5410 | X-charge: X 5411 | 5412 | 5413 | Combinations: 5414 | 5415 | Hypercharge: Y 5416 | 5417 | Y = (B + S + C + B′ + T) 5418 | Y = 2 (Q − I3) 5419 | 5420 | 5421 | Weak hypercharge: YW 5422 | 5423 | YW = 2 (Q − T3) 5424 | X + 2YW = 5 (B − L) 5425 | 5426 | 5427 | 5428 | 5429 | 5430 | Flavour mixing 5431 | 5432 | 5433 | CKM matrix 5434 | PMNS matrix 5435 | Flavour complementarity 5436 | 5437 | 5438 | 5439 | This box: 5440 | 5441 | view 5442 | talk 5443 | edit 5444 | 5445 | 5446 | 5447 | 5448 | 5449 | 5450 | Pauli exclusion principle 5451 | alpha particles 5452 | Alpha particle 5453 | 5454 | 5455 | 5456 | 5457 | 5458 | Alpha decay 5459 | 5460 | 5461 | 5462 | Composition 5463 | 2 protons, 2 neutrons 5464 | 5465 | 5466 | Statistics 5467 | Bosonic 5468 | 5469 | 5470 | Symbol 5471 | α, α2+, He2+ 5472 | 5473 | 5474 | Mass 5475 | 5476 | 6.64465675(29)×10−27 kg[1] 5477 | 4.001506179125(62) u 5478 | 3.727379240(82) GeV/c2 5479 | 5480 | 5481 | Electric charge 5482 | 2 e 5483 | 5484 | 5485 | Spin 5486 | 0[2] 5487 | 5488 | 5489 | standard deviations 5490 | dineutron 5491 | radioactive decay 5492 | particle accelerators 5493 | neutron's magnetic moment 5494 | moderate 5495 | subatomic 5496 | joules 5497 | 5498 | 5499 | 5500 | SI multiples for joule (J) 5501 | 5502 | Submultiples 5503 | 5504 | Multiples 5505 | 5506 | 5507 | Value 5508 | Symbol 5509 | Name 5510 | Value 5511 | Symbol 5512 | Name 5513 | 5514 | 5515 | 10−1 J 5516 | dJ 5517 | decijoule 5518 | 101 J 5519 | daJ 5520 | decajoule 5521 | 5522 | 5523 | 10−2 J 5524 | cJ 5525 | centijoule 5526 | 102 J 5527 | hJ 5528 | hectojoule 5529 | 5530 | 5531 | 10−3 J 5532 | mJ 5533 | millijoule 5534 | 103 J 5535 | kJ 5536 | kilojoule 5537 | 5538 | 5539 | 10−6 J 5540 | µJ 5541 | microjoule 5542 | 106 J 5543 | MJ 5544 | megajoule 5545 | 5546 | 5547 | 10−9 J 5548 | nJ 5549 | nanojoule 5550 | 109 J 5551 | GJ 5552 | gigajoule 5553 | 5554 | 5555 | 10−12 J 5556 | pJ 5557 | picojoule 5558 | 1012 J 5559 | TJ 5560 | terajoule 5561 | 5562 | 5563 | 10−15 J 5564 | fJ 5565 | femtojoule 5566 | 1015 J 5567 | PJ 5568 | petajoule 5569 | 5570 | 5571 | 10−18 J 5572 | aJ 5573 | attojoule 5574 | 1018 J 5575 | EJ 5576 | exajoule 5577 | 5578 | 5579 | 10−21 J 5580 | zJ 5581 | zeptojoule 5582 | 1021 J 5583 | ZJ 5584 | zettajoule 5585 | 5586 | 5587 | 10−24 J 5588 | yJ 5589 | yoctojoule 5590 | 1024 J 5591 | YJ 5592 | yottajoule 5593 | 5594 | 5595 | Common multiples are in bold face 5596 | 5597 | 5598 | 5599 | 5600 | 5601 | charged 5602 | 5603 | Flavour in particle physics 5604 | 5605 | 5606 | Flavour quantum numbers: 5607 | 5608 | Isospin: I or I3 5609 | Charm: C 5610 | Strangeness: S 5611 | Topness: T 5612 | Bottomness: B′ 5613 | 5614 | 5615 | Related quantum numbers: 5616 | 5617 | Baryon number: B 5618 | Lepton number: L 5619 | Weak isospin: T or T3 5620 | Electric charge: Q 5621 | X-charge: X 5622 | 5623 | 5624 | Combinations: 5625 | 5626 | Hypercharge: Y 5627 | 5628 | Y = (B + S + C + B′ + T) 5629 | Y = 2 (Q − I3) 5630 | 5631 | 5632 | Weak hypercharge: YW 5633 | 5634 | YW = 2 (Q − T3) 5635 | X + 2YW = 5 (B − L) 5636 | 5637 | 5638 | 5639 | 5640 | 5641 | Flavour mixing 5642 | 5643 | 5644 | CKM matrix 5645 | PMNS matrix 5646 | Flavour complementarity 5647 | 5648 | 5649 | 5650 | This box: 5651 | 5652 | view 5653 | talk 5654 | edit 5655 | 5656 | 5657 | 5658 | 5659 | 5660 | 5661 | moderation 5662 | isotope 5663 | magnetic fields 5664 | plutonium-239 5665 | fission 5666 | tetraneutrons 5667 | protons 5668 | Proton 5669 | 5670 | 5671 | The quark structure of the proton. (The color assignment of individual quarks is not important, only that all three colors are present.) 5672 | 5673 | 5674 | 5675 | Classification 5676 | Baryon 5677 | 5678 | 5679 | Composition 5680 | 2 up quarks, 1 down quark 5681 | 5682 | 5683 | Statistics 5684 | Fermionic 5685 | 5686 | 5687 | Interactions 5688 | Gravity, Electromagnetic, Weak, Strong 5689 | 5690 | 5691 | Symbol 5692 | p, p+, N+ 5693 | 5694 | 5695 | Antiparticle 5696 | Antiproton 5697 | 5698 | 5699 | Theorized 5700 | William Prout (1815) 5701 | 5702 | 5703 | Discovered 5704 | Ernest Rutherford (1917–1919, named by him, 1920) 5705 | 5706 | 5707 | Mass 5708 | 5709 | 1.672621777(74)×10−27 kg[1] 5710 | 938.272046(21) MeV/c2[1] 5711 | 1.007276466812(90) u[1] 5712 | 5713 | 5714 | Mean lifetime 5715 | >2.1×1029 years (stable) 5716 | 5717 | 5718 | Electric charge 5719 | +1 e 5720 | 1.602176565(35)×10−19 C[1] 5721 | 5722 | 5723 | Charge radius 5724 | 0.8775(51) fm[1] 5725 | 5726 | 5727 | Electric dipole moment 5728 | <5.4×10−24 e·cm 5729 | 5730 | 5731 | Electric polarizability 5732 | 1.20(6)×10−3 fm3 5733 | 5734 | 5735 | Magnetic moment 5736 | 5737 | 1.410606743(33)×10−26 J·T−1[1] 5738 | 1.521032210(12)×10−3 μB[1] 5739 | 2.792847356(23) μN[1] 5740 | 5741 | 5742 | Magnetic polarizability 5743 | 1.9(5)×10−4 fm3 5744 | 5745 | 5746 | Spin 5747 | 1⁄2 5748 | 5749 | 5750 | Isospin 5751 | 1⁄2 5752 | 5753 | 5754 | Parity 5755 | +1 5756 | 5757 | 5758 | Condensed 5759 | I(JP) = 1⁄2(1⁄2+) 5760 | 5761 | 5762 | mass 5763 | University of Cambridge 5764 | Rankings 5765 | 5766 | ARWU[11] 5767 | (2013, national) 5768 | 1 5769 | 5770 | 5771 | ARWU[11] 5772 | (2013, world) 5773 | 5 5774 | 5775 | 5776 | QS[12] 5777 | (2013/14, national) 5778 | 1 5779 | 5780 | 5781 | QS[12] 5782 | (2013/14, world) 5783 | 3 5784 | 5785 | 5786 | THE[13] 5787 | (2013/14, national) 5788 | =2 5789 | 5790 | 5791 | THE[13] 5792 | (2013/14, world) 5793 | =7 5794 | 5795 | 5796 | THE Reputation[115] 5797 | (2014, national) 5798 | 1 5799 | 5800 | 5801 | THE Reputation[115] 5802 | (2014, world) 5803 | 4 5804 | 5805 | 5806 | 5807 | 5808 | 5809 | Complete[116] 5810 | (2015, national) 5811 | 1 5812 | 5813 | 5814 | The Guardian[117] 5815 | (2015, national) 5816 | 1 5817 | 5818 | 5819 | Times/Sunday Times[118] 5820 | (2014, national) 5821 | 1 5822 | 5823 | 5824 | condensed matter 5825 | depleted uranium 5826 | reactivity 5827 | Boltzmann distributed 5828 | Maxwell–Boltzmann 5829 | 5830 | 5831 | Probability density function 5832 | 5833 | 5834 | 5835 | 5836 | Cumulative distribution function 5837 | 5838 | 5839 | 5840 | Parameters 5841 | 5842 | 5843 | 5844 | Support 5845 | 5846 | 5847 | 5848 | pdf 5849 | 5850 | 5851 | 5852 | CDF 5853 | where erf is the Error function 5854 | 5855 | 5856 | Mean 5857 | 5858 | 5859 | 5860 | Mode 5861 | 5862 | 5863 | 5864 | Variance 5865 | 5866 | 5867 | 5868 | Skewness 5869 | 5870 | 5871 | 5872 | Ex. kurtosis 5873 | 5874 | 5875 | 5876 | Entropy 5877 | 5878 | 5879 | 5880 | thermonuclear weapons 5881 | electron capture 5882 | neutron probe 5883 | atom 5884 | boron 5885 | 5886 | Boron 5887 | 5888 | 5889 | 5B 5890 | 5891 | 5892 | 5893 | 5894 | 5895 | 5896 | 5897 | 5898 | 5899 | 5900 | 5901 | 5902 | 5903 | 5904 | 5905 | 5906 | 5907 | 5908 | 5909 | 5910 | 5911 | 5912 | 5913 | 5914 | 5915 | 5916 | 5917 | 5918 | 5919 | 5920 | 5921 | 5922 | 5923 | 5924 | 5925 | 5926 | 5927 | 5928 | 5929 | 5930 | 5931 | 5932 | 5933 | 5934 | 5935 | 5936 | 5937 | 5938 | 5939 | 5940 | 5941 | 5942 | 5943 | 5944 | 5945 | 5946 | 5947 | 5948 | 5949 | 5950 | 5951 | 5952 | 5953 | 5954 | 5955 | 5956 | 5957 | 5958 | 5959 | 5960 | 5961 | 5962 | 5963 | 5964 | 5965 | 5966 | 5967 | 5968 | 5969 | 5970 | 5971 | 5972 | 5973 | 5974 | 5975 | 5976 | 5977 | 5978 | 5979 | 5980 | 5981 | 5982 | 5983 | 5984 | 5985 | 5986 | 5987 | 5988 | 5989 | 5990 | 5991 | 5992 | 5993 | 5994 | 5995 | 5996 | 5997 | 5998 | 5999 | 6000 | 6001 | 6002 | 6003 | 6004 | 6005 | 6006 | 6007 | 6008 | 6009 | 6010 | 6011 | 6012 | 6013 | 6014 | 6015 | 6016 | 6017 | 6018 | 6019 | 6020 | 6021 | 6022 | 6023 | 6024 | 6025 | 6026 | 6027 | 6028 | 6029 | 6030 | 6031 | 6032 | 6033 | 6034 | 6035 | 6036 | 6037 | 6038 | 6039 | 6040 | 6041 | 6042 | 6043 | 6044 | 6045 | 6046 | 6047 | 6048 | 6049 | 6050 | 6051 | 6052 | 6053 | 6054 | 6055 | 6056 | 6057 | 6058 | 6059 | 6060 | 6061 | 6062 | 6063 | 6064 | 6065 | 6066 | 6067 | 6068 | 6069 | 6070 | 6071 | 6072 | 6073 | 6074 | 6075 | 6076 | 6077 | 6078 | 6079 | 6080 | 6081 | 6082 | 6083 | 6084 | 6085 | 6086 | 6087 | 6088 | 6089 | 6090 | 6091 | 6092 | 6093 | 6094 | 6095 | 6096 | 6097 | 6098 | 6099 | 6100 | 6101 | 6102 | 6103 | 6104 | 6105 | 6106 | 6107 | 6108 | 6109 | 6110 | 6111 | 6112 | 6113 | 6114 | 6115 | 6116 | 6117 | 6118 | 6119 | 6120 | 6121 | 6122 | 6123 | 6124 | 6125 | 6126 | 6127 | 6128 | 6129 | 6130 | 6131 | 6132 | 6133 | 6134 | 6135 | 6136 | 6137 | 6138 | 6139 | 6140 | 6141 | 6142 | 6143 | 6144 | 6145 | 6146 | 6147 | 6148 | 6149 | 6150 | 6151 | 6152 | 6153 | 6154 | 6155 | 6156 | 6157 | 6158 | 6159 | 6160 | 6161 | 6162 | 6163 | 6164 | 6165 | 6166 | 6167 | 6168 | 6169 | 6170 | 6171 | 6172 | 6173 | 6174 | 6175 | 6176 | 6177 | 6178 | 6179 | 6180 | 6181 | 6182 | 6183 | 6184 | 6185 | 6186 | 6187 | 6188 | 6189 | 6190 | 6191 | 6192 | 6193 | 6194 | 6195 | 6196 | 6197 | 6198 | 6199 | 6200 | 6201 | 6202 | 6203 | 6204 | 6205 | 6206 | 6207 | 6208 | 6209 | 6210 | 6211 | 6212 | 6213 | 6214 | 6215 | 6216 | 6217 | 6218 | 6219 | 6220 | 6221 | 6222 | 6223 | 6224 | 6225 | 6226 | 6227 | 6228 | 6229 | 6230 | 6231 | 6232 | 6233 | 6234 | 6235 | 6236 | 6237 | 6238 | 6239 | 6240 | 6241 | 6242 | 6243 | 6244 | 6245 | 6246 | 6247 | 6248 | 6249 | 6250 | 6251 | 6252 | 6253 | 6254 | 6255 | 6256 | 6257 | 6258 | 6259 | 6260 | 6261 | 6262 | 6263 | 6264 | 6265 | 6266 | 6267 | 6268 | 6269 | 6270 | 6271 | 6272 | 6273 | 6274 | 6275 | 6276 | - 6277 | ↑ 6278 | B 6279 | ↓ 6280 | Al 6281 | 6282 | 6283 | beryllium ← boron → carbon 6284 | 6285 | 6286 | 6287 | 6288 | 6289 | 6290 | 6291 | 6292 | Boron in the periodic table 6293 | 6294 | 6295 | Appearance 6296 | 6297 | 6298 | black-brown 6299 | 6300 | Boron, shown here in the form of its β-rhombohedral phase (its most thermodynamically stable allotrope)[1] 6301 | 6302 | 6303 | General properties 6304 | 6305 | 6306 | Name, symbol, number 6307 | boron, B, 5 6308 | 6309 | 6310 | Pronunciation 6311 | /ˈbɔərɒn/ 6312 | 6313 | 6314 | Element category 6315 | metalloid 6316 | 6317 | 6318 | Group, period, block 6319 | 13, 2, p 6320 | 6321 | 6322 | Standard atomic weight 6323 | 10.81(1) 6324 | 6325 | 6326 | Electron configuration 6327 | [He] 2s2 2p1 6328 | 2, 3 6329 | 6330 | 6331 | Physical properties 6332 | 6333 | 6334 | Phase 6335 | solid 6336 | 6337 | 6338 | Liquid density at m.p. 6339 | 2.08 g·cm−3 6340 | 6341 | 6342 | Melting point 6343 | 2349 K, 2076 °C, 3769 °F 6344 | 6345 | 6346 | Boiling point 6347 | 4200 K, 3927 °C, 7101 °F 6348 | 6349 | 6350 | Heat of fusion 6351 | 50.2 kJ·mol−1 6352 | 6353 | 6354 | Heat of vaporization 6355 | 508 kJ·mol−1 6356 | 6357 | 6358 | Molar heat capacity 6359 | 11.087 J·mol−1·K−1 6360 | 6361 | 6362 | Vapor pressure 6363 | 6364 | 6365 | 6366 | 6367 | 6368 | P (Pa) 6369 | 1 6370 | 10 6371 | 100 6372 | 1 k 6373 | 10 k 6374 | 100 k 6375 | 6376 | 6377 | at T (K) 6378 | 2348 6379 | 2562 6380 | 2822 6381 | 3141 6382 | 3545 6383 | 4072 6384 | 6385 | 6386 | 6387 | 6388 | 6389 | Atomic properties 6390 | 6391 | 6392 | Oxidation states 6393 | 3, 2, 1[2] 6394 | (mildly acidic oxide) 6395 | 6396 | 6397 | Electronegativity 6398 | 2.04 (Pauling scale) 6399 | 6400 | 6401 | Ionization energies 6402 | (more) 6403 | 1st: 800.6 kJ·mol−1 6404 | 6405 | 6406 | 2nd: 2427.1 kJ·mol−1 6407 | 6408 | 6409 | 3rd: 3659.7 kJ·mol−1 6410 | 6411 | 6412 | Atomic radius 6413 | 90 pm 6414 | 6415 | 6416 | Covalent radius 6417 | 84±3 pm 6418 | 6419 | 6420 | Van der Waals radius 6421 | 192 pm 6422 | 6423 | 6424 | Miscellanea 6425 | 6426 | 6427 | Crystal structure 6428 | rhombohedral 6429 | 6430 | 6431 | 6432 | 6433 | Magnetic ordering 6434 | diamagnetic[3] 6435 | 6436 | 6437 | Electrical resistivity 6438 | (20 °C) ~106 Ω·m 6439 | 6440 | 6441 | Thermal conductivity 6442 | 27.4 W·m−1·K−1 6443 | 6444 | 6445 | Thermal expansion 6446 | (25 °C) (β form) 5–7[4] µm·m−1·K−1 6447 | 6448 | 6449 | Speed of sound (thin rod) 6450 | (20 °C) 16,200 m·s−1 6451 | 6452 | 6453 | Mohs hardness 6454 | ~9.5 6455 | 6456 | 6457 | CAS registry number 6458 | 7440-42-8 6459 | 6460 | 6461 | History 6462 | 6463 | 6464 | Discovery 6465 | Joseph Louis Gay-Lussac and Louis Jacques Thénard[5] (30 June 1808) 6466 | 6467 | 6468 | First isolation 6469 | Humphry Davy[6] (9 July 1808) 6470 | 6471 | 6472 | Most stable isotopes 6473 | 6474 | 6475 | Main article: Isotopes of boron 6476 | 6477 | 6478 | 6479 | 6480 | 6481 | iso 6482 | NA 6483 | half-life 6484 | DM 6485 | DE (MeV) 6486 | DP 6487 | 6488 | 6489 | 10B 6490 | 19.9(7)% 6491 | 10B is stable with 5 neutrons[7] 6492 | 6493 | 6494 | 11B 6495 | 80.1(7)% 6496 | 11B is stable with 6 neutrons[7] 6497 | 6498 | 6499 | 10B content may be as low as 19.1% and as high as 20.3% in natural samples. 11B is the remainder in such cases.[8] 6500 | 6501 | 6502 | 6503 | 6504 | 6505 | 6506 | 6507 | 6508 | view 6509 | talk 6510 | edit 6511 | 6512 | 6513 | · references 6514 | 6515 | 6516 | ordinary water 6517 | CANDU 6518 | cosmic rays 6519 | hydrogen-1 6520 | up quark 6521 | Up quark 6522 | 6523 | Composition 6524 | Elementary particle 6525 | 6526 | 6527 | Statistics 6528 | Fermionic 6529 | 6530 | 6531 | Generation 6532 | First 6533 | 6534 | 6535 | Interactions 6536 | Strong, Weak, Electromagnetic force, Gravity 6537 | 6538 | 6539 | Symbol 6540 | u 6541 | 6542 | 6543 | Antiparticle 6544 | Up antiquark (u) 6545 | 6546 | 6547 | Theorized 6548 | Murray Gell-Mann (1964) 6549 | George Zweig (1964) 6550 | 6551 | 6552 | Discovered 6553 | SLAC (1968) 6554 | 6555 | 6556 | Mass 6557 | 2.3+0.7 6558 | −0.5 MeV/c2[1] 6559 | 6560 | 6561 | Decays into 6562 | Stable or Down quark + Positron + Electron neutrino 6563 | 6564 | 6565 | Electric charge 6566 | +2⁄3 e 6567 | 6568 | 6569 | Color charge 6570 | Yes 6571 | 6572 | 6573 | Spin 6574 | 1⁄2 6575 | 6576 | 6577 | Weak isospin 6578 | LH: +1⁄2, RH: 0 6579 | 6580 | 6581 | Weak hypercharge 6582 | LH: +1⁄3, RH: +4⁄3 6583 | 6584 | 6585 | electric dipole moment 6586 | antiproton 6587 | Antiproton 6588 | 6589 | 6590 | The quark structure of the antiproton. 6591 | 6592 | 6593 | 6594 | Classification 6595 | Antibaryon 6596 | 6597 | 6598 | Composition 6599 | 2 up antiquarks, 1 down antiquark 6600 | 6601 | 6602 | Statistics 6603 | Fermionic 6604 | 6605 | 6606 | Interactions 6607 | Strong, Weak, Electromagnetic, Gravity 6608 | 6609 | 6610 | Status 6611 | Discovered 6612 | 6613 | 6614 | Symbol 6615 | p 6616 | 6617 | 6618 | Particle 6619 | Proton 6620 | 6621 | 6622 | Discovered 6623 | Emilio Segrè & Owen Chamberlain (1955) 6624 | 6625 | 6626 | Mass 6627 | 938 MeV/c2 6628 | 6629 | 6630 | Electric charge 6631 | −1 e 6632 | 6633 | 6634 | Spin 6635 | 1⁄2 6636 | 6637 | 6638 | Isospin 6639 | 1⁄2 6640 | 6641 | 6642 | magnetic 6643 | prompt gamma neutron activation analysis 6644 | heavy nuclei 6645 | chain reaction 6646 | Maxwell–Boltzmann distribution 6647 | Maxwell–Boltzmann 6648 | 6649 | 6650 | Probability density function 6651 | 6652 | 6653 | 6654 | 6655 | Cumulative distribution function 6656 | 6657 | 6658 | 6659 | Parameters 6660 | 6661 | 6662 | 6663 | Support 6664 | 6665 | 6666 | 6667 | pdf 6668 | 6669 | 6670 | 6671 | CDF 6672 | where erf is the Error function 6673 | 6674 | 6675 | Mean 6676 | 6677 | 6678 | 6679 | Mode 6680 | 6681 | 6682 | 6683 | Variance 6684 | 6685 | 6686 | 6687 | Skewness 6688 | 6689 | 6690 | 6691 | Ex. kurtosis 6692 | 6693 | 6694 | 6695 | Entropy 6696 | 6697 | 6698 | 6699 | alpha particle 6700 | Alpha particle 6701 | 6702 | 6703 | 6704 | 6705 | 6706 | Alpha decay 6707 | 6708 | 6709 | 6710 | Composition 6711 | 2 protons, 2 neutrons 6712 | 6713 | 6714 | Statistics 6715 | Bosonic 6716 | 6717 | 6718 | Symbol 6719 | α, α2+, He2+ 6720 | 6721 | 6722 | Mass 6723 | 6724 | 6.64465675(29)×10−27 kg[1] 6725 | 4.001506179125(62) u 6726 | 3.727379240(82) GeV/c2 6727 | 6728 | 6729 | Electric charge 6730 | 2 e 6731 | 6732 | 6733 | Spin 6734 | 0[2] 6735 | 6736 | 6737 | transient 6738 | citation needed 6739 | kinetic theory 6740 | map[collection:3 used:7 frequency:3 computed:1 each:1 tf–idf:13 frequency–inverse:3 frequency,:3 fact:3 for:9 intended:3 value:3 query.:2 it:4 article:8 sources:4 introducing:4 (July:4 tf–idf,:3 or:3 retrieval:3 tf-idf:3 user:2 One:1 query:1 citations.:8 factor:3 functions:2 free:7 precise:4 word:9 given:2 sophisticated:1 from:6 insufficient:4 tool:2 as:5 offset:3 than:3 successfully:2 fields:2 list:4 engines:2 stop-words:2 summing:1 variants:1 document,:3 scheme:2 subject:2 term;:1 unclear:4 short:3 numerical:3 statistic:3 information:3 times:3 common:3 search:2 the:29 of:14 remain:4 because:4 reflect:3 document's:2 encyclopedia:7 important:3 words:3 others.:3 scoring:2 simple:1 but:7 appears:3 generally:3 filtering:2 document:6 and:7 be:2 various:2 simplest:1 many:1 references,:4 its:4 The:3 proportionally:3 number:3 helps:3 summarization:2 can:2 has:4 inline:4 Variations:2 This:4 text:5 that:6 how:3 Wikipedia,:7 by:10 corpus.[1]:8:3 ranking:4 From:7 :17 includes:4 Please:4 2012):4 increases:3 are:6 to:16 improve:4 control:3 relevance:2 (Redirected:6 this:5 It:3 mining.:3 including:2 a:28 more:8 corpus,:3 some:3 central:2 Tf-idf):6 help:4 term:3 is:16 in:16 often:5 weighting:5 which:3 model.:1 classification.:2] 6741 | -------------------------------------------------------------------------------- /stopwords.csv: -------------------------------------------------------------------------------- 1 | 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-------------------------------------------------------------------------------- /utils/get.go: -------------------------------------------------------------------------------- 1 | 2 | package utils 3 | 4 | import ( 5 | "log" 6 | "github.com/PuerkitoBio/goquery" 7 | "strings" 8 | ) 9 | 10 | const baseUrl string = "http://en.wikipedia.org" 11 | const SearchURLPrefix string = "http://en.wikipedia.org/wiki/" 12 | const Selector string = "#mw-content-text p a" 13 | const imageSelector string = "#mw-content-text table.infobox tbody tr td a img" 14 | const InfoCardSelector string = ".infobox" 15 | 16 | func Scrape(url,selector string) (map[string]string) { 17 | var doc *goquery.Document 18 | var e error 19 | if doc, e = goquery.NewDocument(url); e != nil { 20 | log.Fatal(e) 21 | } 22 | urlMap := make(map[string]string) 23 | 24 | doc.Find(selector).Each(func(i int, s *goquery.Selection) { 25 | if s.Text() != "" { 26 | link,_ := s.Attr("href") 27 | if !strings.HasPrefix(link,"//") && strings.HasPrefix(link,"/wiki"){ 28 | 29 | // link="http:"+link 30 | urlMap[s.Text()] = baseUrl+link 31 | } 32 | 33 | } 34 | }) 35 | 36 | return urlMap 37 | } 38 | 39 | func GetInfoCardText(url,selector string) string { 40 | var doc *goquery.Document 41 | var e error 42 | var infoCardText string 43 | if doc, e = goquery.NewDocument(url); e != nil { 44 | log.Fatal(e) 45 | } 46 | 47 | doc.Find(InfoCardSelector).Each(func(i int, s *goquery.Selection) { 48 | infoCardText = s.Text() 49 | 50 | }); 51 | return infoCardText 52 | } 53 | -------------------------------------------------------------------------------- /utils/utils.go: -------------------------------------------------------------------------------- 1 | // utils.go 2 | // Implements utilities for the primary clustering methods 3 | package utils 4 | 5 | import ( 6 | "encoding/csv" 7 | "os" 8 | "strings" 9 | "regexp" 10 | ) 11 | 12 | // func ReadRecords(fileName string) (s [][]string, err error) { 13 | // file, err := os.Open(fileName) 14 | // if err != nil { 15 | // return nil, err 16 | // } 17 | // defer file.Close() 18 | 19 | // reader := csv.NewReader(file) 20 | // reader.TrailingComma = true 21 | 22 | // recordArray, err := reader.ReadAll() 23 | // if err != nil { 24 | // return nil, err 25 | // } 26 | // return recordArray, nil 27 | // } 28 | 29 | func RemoveDuplicates(words []string) []string { 30 | newWords := make([]string, len(words)) 31 | for _, word := range words { 32 | contains := false 33 | for _, w := range newWords { 34 | if strings.EqualFold(w, word) { 35 | contains = true 36 | break 37 | } 38 | } 39 | if !contains { 40 | newWords = append(newWords, word) 41 | } 42 | } 43 | return newWords 44 | } 45 | 46 | func WordFrequency(words []string) (s map[string] int) { 47 | wordCountMap := make(map[string] int) 48 | for _, word := range words { 49 | if strings.EqualFold(word, "") { 50 | continue 51 | } 52 | if _, ok := wordCountMap[word]; ok { 53 | wordCountMap[word]++ 54 | } else { 55 | wordCountMap[word] = 1 56 | } 57 | } 58 | return wordCountMap 59 | } 60 | 61 | func RemoveStopwords(words []string) (s []string, err error) { 62 | stopwords, err := stopwords() 63 | if err != nil { 64 | return nil, err 65 | } 66 | 67 | for _, word := range stopwords { 68 | in, i := wordInList(word, words); 69 | for in { 70 | words = words[:i+copy(words[i:], words[i+1:])] 71 | in, i = wordInList(word, words) 72 | } 73 | } 74 | return words, nil 75 | } 76 | 77 | func LowercaseWords(words []string) []string { 78 | for i := range words { 79 | words[i] = strings.ToLower(words[i]) 80 | } 81 | return words 82 | } 83 | 84 | func RemoveNonAlphaNumeric(s string) (str string, err error) { 85 | r, err := regexp.Compile("[^\\w]|[-+]?\\d+") 86 | if err != nil { 87 | return "", err 88 | } 89 | return r.ReplaceAllString(s, ""), nil 90 | } 91 | 92 | func stopwords() (s []string, err error) { 93 | file, err := os.Open("stopwords.csv") 94 | if err != nil { 95 | return nil, err 96 | } 97 | defer file.Close() 98 | record, err := csv.NewReader(file).Read() 99 | if err != nil { 100 | return nil, err 101 | } 102 | return record, nil 103 | } 104 | 105 | func wordInList(a string, list []string) (b bool, index int) { 106 | for i, b := range list { 107 | if b == a { 108 | return true, i 109 | } 110 | } 111 | return false, -1 112 | } 113 | --------------------------------------------------------------------------------