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Isotopes of boron

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(Redirected from Boron-7)

Isotopes of boron (5B)
Main isotopes[1] Decay
Isotope abun­dance half-life (t1/2) mode pro­duct
8B synth 771.9 ms β+ 8Be
10B [18.9%, 20.4%] stable
11B [79.6%, 81.1%] stable
Standard atomic weight Ar°(B)

Boron (5B) naturally occurs as isotopes 10
B
and 11
B
, 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 8
B
, with a half-life of only 771.9(9) ms and 12
B
with a half-life of 20.20(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 while those with mass above 11 mostly become carbon.

List of isotopes

[edit]
Nuclide
Z N Isotopic mass (Da)[4]
[n 1]
Discovery
year[5]
Half-life[1]

[resonance width]
Decay
mode
[1]
[n 2]
Daughter
isotope

[n 3]
Spin and
parity[1]
[n 4][n 5]
Natural abundance (mole fraction)
Normal proportion[1] Range of variation
7
B
5 2 7.029712(27) 1967 570(14) ys
[801(20) keV]
p 6
Be
[n 6]
(3/2−)
8
B
[n 7][n 8]
5 3 8.0246073(11) 1950 771.9(9) ms β+ 8
Be
[n 9]
2+
9
B
5 4 9.0133296(10) 1940 800(300) zs p 8
Be
[n 10]
3/2−
10
B
[n 11]
5 5 10.012936862(16) 1920 Stable 3+ [0.189, 0.204][6]
11
B
5 6 11.009305167(13) 1920 Stable 3/2− [0.796, 0.811][6]
12
B
5 7 12.0143526(14) 1935 20.20(2) ms β (99.40(2)%) 12
C
1+
βα (0.60(2)%) 8
Be
[n 12]
13
B
5 8 13.0177800(11) 1956 17.16(18) ms β (99.734(36)%) 13
C
3/2−
βn (0.266(36)%) 12
C
14
B
5 9 14.025404(23) 1966 12.36(29) ms β (93.96(23)%) 14
C
2−
βn (6.04(23)%) 13
C
β2n ?[n 13] 12
C
 ?
15
B
5 10 15.031087(23) 1966 10.18(35) ms βn (98.7(1.0)%) 14
C
3/2−
β (< 1.3%) 15
C
β2n (< 1.5%) 13
C
16
B
5 11 16.039841(26) 2000 > 4.6 zs n ?[n 13] 15
B
 ?
0−
17
B
[n 14]
5 12 17.04693(22) 1973 5.08(5) ms βn (63(1)%) 16
C
(3/2−)
β (21.1(2.4)%) 17
C
β2n (12(2)%) 15
C
β3n (3.5(7)%) 14
C
β4n (0.4(3)%) 13
C
18
B
5 13 18.05560(22) 2010 < 26 ns n 17
B
(2−)
19
B
[n 15]
5 14 19.06417(56) 1984 2.92(13) ms βn (71(9)%) 18
C
(3/2−)
β2n (17(5)%) 17
C
β3n (< 9.1%) 16
C
β (> 2.9%) 19
C
20
B
[7]
5 15 20.07451(59) 2018 > 912.4 ys n 19
B
(1−, 2−)
21
B
[7]
5 16 21.08415(60) 2018 > 760 ys 2n 19
B
(3/2−)
This table header & footer:
  1. ()  Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  2. Modes of decay:
    n:Neutron emission
    p:Proton emission
  3. Bold symbol as daughter  Daughter product is stable.
  4. () spin value  Indicates spin with weak assignment arguments.
  5. #  Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  6. Subsequently decays by double proton emission to 4
    He
    for a net reaction of 7
    B
    4
    He
    + 31
    H
  7. Has 1 halo proton
  8. Intermediate product of a branch of proton–proton chain in stellar nucleosynthesis as part of the process converting hydrogen to helium
  9. Immediately decays into two α particles, for a net reaction of 8
    B
    → 24
    He
    + e+
  10. Immediately decays into two α particles, for a net reaction of 9
    B
    → 24
    He
    + 1
    H
  11. One of the few stable odd-odd nuclei
  12. Immediately decays into two α particles, for a net reaction of 12
    B
    → 34
    He
    + e
  13. 1 2 Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.
  14. Has 2 halo neutrons
  15. Has 4 halo neutrons

Boron-8

[edit]

Boron-8 is an isotope of boron that undergoes β+ decay to beryllium-8 with a half-life of 771.9(9) ms. It is the strongest candidate for a halo nucleus with a loosely-bound proton, in contrast to neutron halo nuclei such as lithium-11.[8]

Although boron-8 beta decay neutrinos from the Sun make up only about 80 ppm of the total solar neutrino flux, they have a higher energy centered around 10 MeV,[9] and 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.

Applications

[edit]

Boron-10

[edit]

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

See also

[edit]

Daughter products other than boron

References

[edit]
  1. 1 2 3 4 5 Kondev, 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.
  2. "Standard Atomic Weights: Boron". CIAAW. 2009.
  3. 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.
  4. 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.
  5. FRIB Nuclear Data Group. "Discovery of Nuclides Project, Isotope Database". doi:10.11578/frib/2279152.
  6. 1 2 "Atomic Weight of Boron". CIAAW.
  7. 1 2 Leblond, S.; et al. (2018). "First observation of 20B and 21B". Physical Review Letters. 121 (26): 262502–1–262502–6. arXiv:1901.00455. doi:10.1103/PhysRevLett.121.262502. PMID 30636115. S2CID 58602601.
  8. 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.
  9. 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.
  10. 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.


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