Question

Define isotones with an example

Answer 1

Definition

• Isotones are two or more species of atoms or nuclei that have the same number of neutrons.
• Their atomic number(Z) and mass number (A) are different. But the value $\mathrm{A}-\mathrm{Z}$( number of neutrons) is the same.

Example

${}_{17}{}^{37}\mathrm{Cl}$ and ${}_{19}{}^{39}\mathrm{K}$ are isotones. The atomic nucleus of Chlorine consists of 17 protons and 20 neutrons. Whereas the nucleus of the species Potassium contains 19 protons and 20 neutrons.