Complete the following nuclear changes —

(a) $_{x}^{a}\text{P} \longrightarrow Q + _{-1}^{0}\text{β}$
n
(b) $_{92}^{238}\text{U} \longrightarrow \space _{90}^{234}\text{Th} + …… + \text{energy}$

(c) $_{92}^{238}\text{P} \overset{\alpha} \longrightarrow \text{Q} \overset{\beta} \longrightarrow \text{R} \overset{\beta} \longrightarrow \text{S}$

(d) {Z}^{A}\text{X} \overset{\alpha} \longrightarrow \text{X}{1} \overset{\gamma} \longrightarrow \text{X}{2} \overset{2\beta} \longrightarrow \text{X}{3}

(e) $\text{X} \overset{\beta} \longrightarrow \text{X}${1} \overset{\alpha} \longrightarrow \text{X}{2} \overset{\alpha} \longrightarrow \space {69}^{172}\text{X}{3}

Why do we usually use isotopes emitting γ radiations as radioactive tracers in medical science?

Name the three constituents of an atom and state mass and charge of each. How are they distributed in an atom?

Define the following terms —

(a) atomic number and (b) mass number.