Radioactivity — Question 12

(a) The number 24 is called the mass number and the number 11 is called the atomic number.

(b) The equation representing β-decay is as follows —

$_{11}^{24}\text{Na} \longrightarrow \space _{12}^{24}\text{Mg} + _{-1}^{\space \space\space 0}\text{e}$

(c) The product nucleus is called the isobar because they have same mass number and different atomic number.