Isotopes of boron

Isotopes of boron (₅B)
Standard atomic weight Ar°(B)
	[10.806, 10.821]; 10.81±0.02 (abridged);

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

Nuclide	Z	N	Isotopic mass (Da)⁴ ^{n 1}	Discovery year⁵	Half-life¹ [resonance width]	Decay mode¹ ^{n 2}	Daughter isotope ^{n 3}	Spin and parity¹ ^{n 4}^{n 5}	Natural abundance (mole fraction)
Nuclide	Z	N	Isotopic mass (Da)⁴ ^{n 1}	Discovery year⁵	Half-life¹ [resonance width]	Decay mode¹ ^{n 2}	Daughter isotope ^{n 3}	Spin and parity¹ ^{n 4}^{n 5}	Normal proportion¹	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+
¹² B	5	7	12.0143526(14)	1935	20.20(2) ms	β⁻α (0.60(2)%)	⁸ Be^{n 12}	1+
¹³ B	5	8	13.0177800(11)	1956	17.16(18) ms	β⁻ (99.734(36)%)	¹³ C	3/2−
¹³ B	5	8	13.0177800(11)	1956	17.16(18) ms	β⁻n (0.266(36)%)	¹² C	3/2−
¹⁴ B	5	9	14.025404(23)	1966	12.36(29) ms	β⁻ (93.96(23)%)	¹⁴ C	2−
						β⁻n (6.04(23)%)	¹³ C
						β⁻2n ?^{n 13}	¹² C ?
¹⁵ B	5	10	15.031087(23)	1966	10.18(35) ms	β⁻n (98.7(1.0)%)	¹⁴ C	3/2−
						β⁻ (< 1.3%)	¹⁵ C
						β⁻2n (< 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	β⁻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	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	β⁻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 B⁷	5	15	20.07451(59)	2018	> 912.4 ys	n	¹⁹ B	(1−, 2−)
²¹ B⁷	5	16	21.08415(60)	2018	> 760 ys	2n	¹⁹ B	(3/2−)
This table header & footer: view

( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
Modes of decay:

n: Neutron emission

p: Proton emission
Bold symbol as daughter – Daughter product is stable.
( ) spin value – Indicates spin with weak assignment arguments.
# – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
Subsequently decays by double proton emission to ⁴
He for a net reaction of ⁷
B → ⁴
He + 3 ¹
H
Has 1 halo proton
Intermediate product of a branch of proton–proton chain in stellar nucleosynthesis as part of the process converting hydrogen to helium
Immediately decays into two α particles, for a net reaction of ⁸
B → 2 ⁴
He + e⁺
Immediately decays into two α particles, for a net reaction of ⁹
B → 2 ⁴
He + ¹
H
One of the few stable odd-odd nuclei
Immediately decays into two α particles, for a net reaction of ¹²
B → 3 ⁴
He + e⁻
Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.
Has 2 halo neutrons
Has 4 halo neutrons

Boron-8

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

Boron-10

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

References

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.
"Standard Atomic Weights: Boron". CIAAW. 2009.
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.
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.
FRIB Nuclear Data Group. "Discovery of Nuclides Project, Isotope Database". doi:10.11578/frib/2279152.
"Atomic Weight of Boron". CIAAW.
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.
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.
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.
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.

[5] ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[7] Modes of decay:

n: Neutron emission

p: Proton emission

[8] Bold symbol as daughter – Daughter product is stable.

[9] ( ) spin value – Indicates spin with weak assignment arguments.

[TNN-10] # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

[11] Subsequently decays by double proton emission to ⁴
He for a net reaction of ⁷
B → ⁴
He + 3 ¹
H

[12] Has 1 halo proton

[13] Intermediate product of a branch of proton–proton chain in stellar nucleosynthesis as part of the process converting hydrogen to helium

[14] Immediately decays into two α particles, for a net reaction of ⁸
B → 2 ⁴
He + e⁺

[15] Immediately decays into two α particles, for a net reaction of ⁹
B → 2 ⁴
He + ¹
H

[16] One of the few stable odd-odd nuclei

[18] Immediately decays into two α particles, for a net reaction of ¹²
B → 3 ⁴
He + e⁻

[decay_mode_1-19] Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.

[hn-20] Has 2 halo neutrons

[21] Has 4 halo neutrons

[NUBASE2020-1] 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.

[CIAAWboron-2] "Standard Atomic Weights: Boron". CIAAW. 2009.

[CIAAW2021-3] 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.

[AME2020_II-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.

[IsotopeFRIB-6] FRIB Nuclear Data Group. "Discovery of Nuclides Project, Isotope Database". doi:10.11578/frib/2279152.

[Atomic_Weight_of_Boron2-17] "Atomic Weight of Boron". CIAAW.

[20B-21B-22] 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.

[23] 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.

[Bellerive2004-24] 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.

[8B-Cerdeno-25] 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.

1

2

3

4

n 1

5

n 2

n 3

n 4

n 5

n 6

n 7

n 8

n 9

n 10

n 11

6

n 12

n 13

n 14

n 15

7

8

9

10

List of isotopes

Boron-8

Applications

Boron-10

See also

References