| 释义 |
- List of isotopes Notes
- Applications Boron-10
- References Notes General references
{{infobox boron isotopes}}{{more citations needed|date=May 2018}}Boron (5B) naturally occurs as isotopes 10B and 11B, the latter of which makes up about 80% of natural boron. There are 13 radioisotopes that have been discovered, with mass numbers from 7 to 21, all with short half-lives, the longest being that of 8B, with a half-life of only 770 milliseconds (ms) and 12B with a half-life of 20.2 ms. All other isotopes have half-lives shorter than 17.35 ms. Those isotopes with mass below 10 decay into helium (via short-lived isotopes of beryllium for 7B and 9B) while those with mass above 11 mostly become carbon. List of isotopes nuclide
symbol | Z(p) | N(n) |
isotopic mass (u)[1]
| half-life
[resonance width][2] | decay mode(s)[3] | daughter
isotope(s) | nuclear
spin and
parity | representative
isotopic
composition
(mole fraction) | range of natural
variation
(mole percent) | | 7B | 5 | {{fsp}}2 | 7.029712(27) | 570(14){{hsp}}×{{hsp}}10−24 s
[801(20) keV] | p | Beryllium|6}}[4] | (3/2−) | | 8B[5] | 5 | {{fsp}}3 | 8.0246073(11) | 770(3) ms | β+, α | {{SimpleNuclide>Helium|4}} | 2+ | | 9B | 5 | {{fsp}}4 | 9.0133296(10) | 800(300){{thinsp}}×{{thinsp}}10−21 s
[0.54(21) keV] | p, α | {{SimpleNuclide>Helium|4}} | 3/2− | | 10B | 5 | {{fsp}}5 | 10.012936862(16) | Stable | 3+ | 0.199(7) | 18.929–20.386 | | 11B | 5 | {{fsp}}6 | 11.009305167(13) | Stable | 3/2− | 0.801(7) | 79.614–81.071 | | 12B | 5 | {{fsp}}7 | 12.0143526(14) | 20.20(2) ms | β− (98.4%) | {{SimpleNuclide>Carbon|12}} | 1+ | | | | β−, α (1.6%) | Beryllium|8}}[6] | | 13B | 5 | {{fsp}}8 | 13.0177800(11) | 17.33(17) ms | β− (99.72%) | {{SimpleNuclide>Carbon|13}} | 3/2− | | | | β−, n (0.28%) | {{SimpleNuclide>Carbon|12}} | | 14B | 5 | {{fsp}}9 | 14.025404(23) | 12.5(5) ms | β− (93.96%) | Carbon|14}} | 2− | | | | β−, n (6.04%) | {{SimpleNuclide>Carbon|13}} | | 15B | 5 | 10 | 15.031088(23) | 9.93(7) ms | β−, n (93.6%) | Carbon|14}} | 3/2− | | | | β− (6.0%) | Carbon|15}} | | β−, 2n (0.4%) | {{SimpleNuclide>Carbon|13}} | | 16B | 5 | 11 | 16.039842(26) | >{{hsp}}4.6{{hsp}}×{{hsp}}10−21 s
| n | Boron|15}} | 0− | | 17B[7] | 5 | 12 | 17.04693(22) | 5.08(5) ms | β−, n (63.0%) | Carbon|16}} | (3/2−) | | | | β− (22.1%) | Carbon|17}} | | β−, 2n (11.0%) | Carbon|15}} | | β−, 3n (3.5%) | Carbon|14}} | | β−, 4n (0.4%) | {{SimpleNuclide>Carbon|13}} | | 18B | 5 | 13 | 18.05560(22) | <{{hsp}}26 ns | n | Boron|17}} | (2−) | | 19B[7] | 5 | 14 | 19.06417(56) | 2.92(13) ms | β−, n (71%) | Carbon|18}} | 3/2−# | | | | β−, 2n (17%) | Carbon|17}} | | β− (12%) | Carbon|19}} | | 20B[8] | 5 | 15 | 20.07348(86)# | [2.50(9) MeV] | n | Boron|19}} | (1−, 2−) | | 21B[8] | 5 | 16 | 21.08302(97)# | <{{hsp}}260 ns
[2.47(19) MeV] | 2n | Boron|19}} | (3/2−)# |
1. ^{{NUBASE 2016 II}}
2. ^{{NUBASE 2016}}
3. ^{{cite web |url=http://www.nucleonica.net/unc.aspx |title=Universal Nuclide Chart |publisher=nucleonica |registration=yes}}
4. ^Subsequently decays by double proton emission to 4He for a net reaction of 7B → 4He + 3{{hsp}}1H
5. ^Has 1 halo proton
6. ^Immediately decays into two α particles, for a net reaction of 12B → 3{{hsp}}4He + {{e-}}
7. ^1 Has 2 halo neutrons
8. ^1 {{cite journal|last=Leblond|first=S.|display-authors=etal|title=First observation of 20B and 21B|journal=Physical Review Letters|volume=121|issue=26|pages=262502–1–262502–6|doi=10.1103/PhysRevLett.121.262502|pmid=30636115|arxiv=1901.00455|year=2018}}
9. ^{{cite web |author= |date= |title=2.5.7. Standard and expanded uncertainties |url=http://www.itl.nist.gov/div898/handbook/mpc/section5/mpc57.htm |work=Engineering Statistics Handbook |publisher= |accessdate=2010-09-16}}
10. ^{{cite journal|last1=Cerdeno|first1=David G.|last2=Fairbairn|first2=Malcolm|last3=Jubb|first3=Thomas|last4=Machado|first4=Pedro|last5=Vincent|first5=Aaron C.|last6=Boehm|first6=Celine|title=Physics from solar neutrinos in dark matter direct detection experiments|journal=JHEP|date=2016|volume=2016|issue=5|page=118|doi=10.1007/JHEP05(2016)118|accessdate=|arxiv=1604.01025|bibcode=2016JHEP...05..118C}}
Notes - The precision of the isotope abundances and atomic mass is limited through variations. The given ranges should be applicable to any normal terrestrial material.
- Commercially available materials may have been subjected to an undisclosed or inadvertent isotopic fractionation. Substantial deviations from the given mass and composition can occur.
- Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
- Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use folical uncertainties.[9]
- Nuclide masses are given by IUPAP Commission on Symbols, Units, Nomenclature, Atomic Masses and Fundamental Constants (SUNAMCO).
- Isotope abundances are given by IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW).
- Neutrinos from boron-8 beta decays within the sun are an important background to dark matter direct detection experiments.[10] They are the first component of the neutrino floor that dark matter direct detection experiments are expected to eventually encounter.
ApplicationsBoron-10Boron-10 is used in boron neutron capture therapy (BNCT) as an experimental treatment of some brain cancers. References NotesGeneral references- Isotope masses from:
- Isotopic compositions and standard atomic masses from:
- {{CAWIA 2003}}
- {{CIAAW 2005}}
- Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- {{NUBASE 2003}}
- {{NNDC}}
- {{CRC85|chapter=11}}
{{Navbox element isotopes}} 3 : Boron|Isotopes of boron|Lists of isotopes by element |