Arrange the α, β and γ radiations in ascending order of their (i) ionizing power, and (ii) penetrating power.

State the speed of each of α, β and γ radiations.

What happens to the (i) atomic number, (ii) mass number of the nucleus of an element when (a) an α particle, (b) a β particle, and (c) γ radiation, is emitted?

State whether the following nuclear disintegrations are allowed or not (star indicate an excited state). Give reason if it is not allowed.

(a) $_{Z}^{A}\text{X} \longrightarrow _{Z}^{A}\text{X} + \gamma$

(b) $_{Z}^{A}\text{X} \longrightarrow \space _{Z-2}^{ \space \space \space \space \space A}\text{X} + \space _{2}^{4}\text{He}$