The number of neutrons in an element is obtained from the difference between the number of atomic masses and the number of atoms.
That is, neutron number (n) = atomic mass number (A) – atomic number (Z)
We know that the atomic number of boron is 5 and the atomic mass number is about 11 (10.81). Neutron = 11 – 5 = 6. Therefore, a boron atom has six neutrons.
|Mass number (A)||Atomic number (Z)||Neutron number = A – Z|
Based on the atomic number, mass number, and neutron number of the element, three things can be considered. These are isotope, isobar, and isotone. The number of neutrons depends on the isotope of the atom. The boron atom has about fifteen isotopes.
List of neutron numbers by an isotope of aluminum
Atoms that have the same number of protons but different mass numbers are called isotopes of each other. The English chemist Frederick Sodi first came up with the idea of isotopes in 1912, and the scientist Aston in 1919 identified two different mass neon atoms (20Ne, 22Ne).
He named the atoms with different masses of the same element as isotopes of that element. The number of protons in an isotope atom does not change but the number of neutrons does.
|Isotope||Mass number (A)||Atomic number (Z)||Neutron number = A – Z|
The boron atom has fifteen isotopes. Among the isotopes, 10B and 11B are stable and are formed naturally. The remaining isotopes of boron are highly unstable and their half-lives are very short.
Of the 15 radioisotopes of boron, the longest being that of 8B, with a half-life of only 771.9 ms, and 12B with a half-life of 20.20 ms. The mass of 10B is about 10 (10.012936), and that of 11B is about 11 (11.009305).