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Isotopes of boron

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Isotopes ofboron (5B)
Main isotopesDecay
abun­dancehalf-life(t1/2)modepro­duct
8Bsynth771.9 msβ+8Be
10B[18.9%, 20.4%]stable
11B[79.6%, 81.1%]stable
Standard atomic weightAr°(B)

Boron (5B) naturally occurs asisotopes10
B
 and11
B
, the latter of which makes up about 80% of natural boron. There are 13radioisotopes that have been discovered, with mass numbers from 7 to 21, all with shorthalf-lives, the longest being that of8
B
, with a half-life of only771.9(9) ms and12
B
 with a half-life of20.20(2) ms. All other isotopes have half-lives shorter than17.35 ms. Those isotopes with mass below 10 decay intohelium (via short-livedisotopes of beryllium for7
B
 and9
B
) while those with mass above 11 mostly becomecarbon.

A chart showing the abundances of the naturally occurring isotopes of boron.

List of isotopes

[edit]
Nuclide
[n 1]		ZNIsotopic mass(Da)[3]
[n 2][n 3]		Half-life[4]

[resonance width]		Decay
mode[4]
[n 4]		Daughter
isotope
[n 5]		Spin and
parity[4]
[n 6][n 7]		Natural abundance(mole fraction)
Excitation energyNormal proportion[4]Range of variation
6
B
?[n 8]		5 16.050800(2150)p-unstable2p?4
Li
?		2−#
7
B
5 27.029712(27)570(14) ys
[801(20) keV]		p6
Be
[n 9]		(3/2−)
8
B
[n 10][n 11]		5 38.0246073(11)771.9(9) msβ+α4
He
2+
8m
B
10624(8) keV0+
9
B
5 49.0133296(10)800(300) zsp8
Be
[n 12]		3/2−
10
B
[n 13]		5 510.012936862(16)Stable3+[0.189,0.204][5]
11
B
5 611.009305167(13)Stable3/2−[0.796,0.811][5]
11m
B
12560(9) keV1/2+, (3/2+)
12
B
5 712.0143526(14)20.20(2) msβ− (99.40(2)%)12
C
1+
β−α (0.60(2)%)8
Be
[n 14]
13
B
5 813.0177800(11)17.16(18) msβ− (99.734(36)%)13
C
3/2−
β−n (0.266(36)%)12
C
14
B
5 914.025404(23)12.36(29) msβ− (93.96(23)%)14
C
2−
β−n (6.04(23)%)13
C
β−2n ?[n 15]12
C
 ?
14m
B
17065(29) keV4.15(1.90) zsIT ?[n 15]0+
15
B
51015.031087(23)10.18(35) msβ−n (98.7(1.0)%)14
C
3/2−
β− (<1.3%)15
C
β−2n (<1.5%)13
C
16
B
51116.039841(26)>4.6 zsn ?[n 15]15
B
 ?		0−
17
B
[n 16]		51217.04693(22)5.08(5) msβ−n (63(1)%)16
C
(3/2−)
β− (21.1(2.4)%)17
C
β−2n (12(2)%)15
C
β−3n (3.5(7)%)14
C
β−4n (0.4(3)%)13
C
18
B
51318.05560(22)<26 nsn17
B
(2−)
19
B
[n 17]		51419.06417(56)2.92(13) msβ−n (71(9)%)18
C
(3/2−)
β−2n (17(5)%)17
C
β−3n (<9.1%)16
C
β− (>2.9%)19
C
20
B
[6]		51520.07451(59)>912.4 ysn19
B
(1−, 2−)
21
B
[6]		51621.08415(60)>760 ys2n19
B
(3/2−)
This table header & footer:
  1. ^mB – Excitednuclear isomer.
  2. ^( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^# – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^Modes of decay:
    n:Neutron emission
    p:Proton emission
  5. ^Bold symbol as daughter – Daughter product is stable.
  6. ^( ) spin value – Indicates spin with weak assignment arguments.
  7. ^# – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  8. ^This isotope has not yet been observed; given data is inferred or estimated from periodic trends.
  9. ^Subsequently decays by double proton emission to4
    He
     for a net reaction of7
    B
     →4
    He
     + 3 1
    H
  10. ^Has 1halo proton
  11. ^Intermediate product ofa branch of proton-proton chain in stellar nucleosynthesis as part of the process converting hydrogen to helium
  12. ^Immediately decays into two α particles, for a net reaction of9
    B
     → 2 4
    He
     +1
    H
  13. ^One of the few stableodd-odd nuclei
  14. ^Immediately decays into two α particles, for a net reaction of12
    B
     → 3 4
    He
     + e−
  15. ^abcDecay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.
  16. ^Has 2 halo neutrons
  17. ^Has 4 halo neutrons

Boron-8

[edit]

Boron-8 is an isotope of boron that undergoes β+ decay toberyllium-8 with a half-life of771.9(9) ms. It is the strongest candidate for ahalo nucleus with a loosely-bound proton, in contrast to neutron halo nuclei such aslithium-11.[7]

Although boron-8 beta decayneutrinos from the Sun make up only about 80 ppm of the totalsolar neutrino flux, they have a higher energy centered around 10 MeV,[8] and are an important background to dark matterdirect detection experiments.[9] They are the first component of the neutrino floor that dark matter direct detection experiments are expected to eventually encounter.

Applications

[edit]

Boron-10

[edit]

Boron-10 is used inboron neutron capture therapy as an experimental treatment of some brain cancers.

References

[edit]
  1. ^"Standard Atomic Weights: Boron".CIAAW. 2009.
  2. ^Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04)."Standard atomic weights of the elements 2021 (IUPAC Technical Report)".Pure and Applied Chemistry.doi:10.1515/pac-2019-0603.ISSN 1365-3075.
  3. ^Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*".Chinese Physics C.45 (3): 030003.doi:10.1088/1674-1137/abddaf.
  4. ^abcdKondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021)."The NUBASE2020 evaluation of nuclear properties"(PDF).Chinese Physics C.45 (3): 030001.doi:10.1088/1674-1137/abddae.
  5. ^ab"Atomic Weight of Boron".CIAAW.
  6. ^abLeblond, S.; et al. (2018). "First observation of20B and21B".Physical Review Letters.121 (26): 262502–1–262502–6.arXiv:1901.00455.doi:10.1103/PhysRevLett.121.262502.PMID 30636115.S2CID 58602601.
  7. ^Maaß, Bernhard; Müller, Peter; Nörtershäuser, Wilfried; Clark, Jason; Gorges, Christian; Kaufmann, Simon; König, Kristian; Krämer, Jörg; Levand, Anthony; Orford, Rodney; Sánchez, Rodolfo; Savard, Guy; Sommer, Felix (November 2017). "Towards laser spectroscopy of the proton-halo candidate boron-8".Hyperfine Interactions.238 (1): 25.Bibcode:2017HyInt.238...25M.doi:10.1007/s10751-017-1399-5.S2CID 254551036.
  8. ^Bellerive, A. (2004). "Review of solar neutrino experiments".International Journal of Modern Physics A.19 (8):1167–1179.arXiv:hep-ex/0312045.Bibcode:2004IJMPA..19.1167B.doi:10.1142/S0217751X04019093.S2CID 16980300.
  9. ^Cerdeno, David G.; Fairbairn, Malcolm; Jubb, Thomas; Machado, Pedro; Vincent, Aaron C.; Boehm, Celine (2016). "Physics from solar neutrinos in dark matter direct detection experiments".JHEP.2016 (5): 118.arXiv:1604.01025.Bibcode:2016JHEP...05..118C.doi:10.1007/JHEP05(2016)118.S2CID 55112052.
Group12 3456789101112131415161718
PeriodHydrogen and
alkali metals		Alkaline
earth metals		Pnicto­gensChal­co­gensHalo­gensNoble gases
①12
②345678910
③1112131415161718
④192021222324252627282930313233343536
⑤373839404142434445464748495051525354
⑥55561 asterisk71727374757677787980818283848586
⑦87881 asterisk103104105106107108109110111112113114115116117118
⑧119120
1 asterisk5758596061626364656667686970 
1 asterisk8990919293949596979899100101102
Authority control databases: NationalEdit this at Wikidata


https://borates.today/isotopes-a-comprehensive-guide/#:~:text=Boron%20isotope%20elements%20with%20masses,11%20mostly%20decay%20into%20carbon.

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