Isotopes of boron
Encyclopedia
Boron
(B) naturally occurs in two isotopes, 10B and 11B, the later of which makes up about 80% of natural boron. 14 radioisotopes have been discovered, with mass numbers from 6 to 21, all with short half-lives
, the longest being that of 8B, with a half-life of only 770 ms and 12B with a half-life of 20.2 milliseconds. All other isotopes have half-lives shorter than 17.35 milliseconds, with the least stable isotope being 7B, with a half-life of 150 yoctoseconds (ys). 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
.
Standard atomic mass: 10.811(7) u
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Boron
Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
(B) naturally occurs in two isotopes, 10B and 11B, the later of which makes up about 80% of natural boron. 14 radioisotopes have been discovered, with mass numbers from 6 to 21, all with short half-lives
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
, the longest being that of 8B, with a half-life of only 770 ms and 12B with a half-life of 20.2 milliseconds. All other isotopes have half-lives shorter than 17.35 milliseconds, with the least stable isotope being 7B, with a half-life of 150 yoctoseconds (ys). Those isotopes with mass below 10 decay into helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
(via short-lived isotopes of beryllium
Beryllium
Beryllium is the chemical element with the symbol Be and atomic number 4. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl and chrysoberyl...
for 7B and 9B) while those with mass above 11 mostly become carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
.
Standard atomic mass: 10.811(7) u
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-life | decay mode(s) | daughter isotope(s) |
nuclear spin |
representative isotopic composition (mole percent) |
range of natural variation (mole percent) |
|---|---|---|---|---|---|---|---|---|---|
| 6B | 5 | 1 | 6.04681(75)# | ||||||
| 7B | 5 | 2 | 7.02992(8) | 350(50)×10−24 s [1.4(2) MeV] |
p Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very... |
Subsequently decays by double proton emission to 4He for a net reaction of 7B → 4He + 31H | (−) | ||
| 8BHas 1 halo proton | 5 | 3 | 8.0246072(11) | 770(3) ms | β+ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a... , fission |
2 | 2+ | ||
| 9B | 5 | 4 | 9.0133288(11) | 800(300)×10−21 s [0.54(21) keV] |
p Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very... |
immediately decays into two α particles, for a net reaction of 9B → 2 4He + 1H | − | ||
| 10B | 5 | 5 | 10.0129370(4) | Stable | 3+ | 19.9(7) | 18.929 – 20.386 | ||
| 11B | 5 | 6 | 11.0093054(4) | Stable | − | 80.1(7) | 79.614–81.071 | ||
| 12B | 5 | 7 | 12.0143521(15) | 20.20(2) ms | β− (98.4%) | 1+ | |||
| β−, α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less... (1.6%) |
Immediately decays into three α particles, for a net reaction of 12B → 34He + | ||||||||
| 13B | 5 | 8 | 13.0177802(12) | 17.33(17) ms | β− (99.72%) | − | |||
| β−, n (0.279%) | |||||||||
| 14B | 5 | 9 | 14.025404(23) | 12.5(5) ms | β− (93.96%) | 2− | |||
| β−, n (6.04%) | |||||||||
| 15B | 5 | 10 | 15.031103(24) | 9.87(7) ms | β−, n (93.6%) | − | |||
| β− (6.0%) | |||||||||
| β−, 2n (0.40%) | |||||||||
| 16B | 5 | 11 | 16.03981(6) | <190×10−12 s [<0.1 MeV] |
n Neutron emission Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13... |
0− | |||
| 17BHas 2 halo neutrons | 5 | 12 | 17.04699(18) | 5.08(5) ms | β−, n (63.0%) | (−) | |||
| β− (22.1%) | |||||||||
| β−, 2n (11.0%) | |||||||||
| β−, 3n (3.5%) | |||||||||
| β−, 4n (0.40%) | |||||||||
| 18B | 5 | 13 | 18.05617(86)# | <26 ns | n | (4−)# | |||
| 19B | 5 | 14 | 19.06373(43)# | 2.92(13) ms | β− | (−)# | |||
General references
- Isotope masses from:
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- Isotopic compositions and standard atomic masses from:
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- Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
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