Question

\[ {}_{86}\mathrm{Rn}^{222} \longrightarrow {}_{\mathrm{y}}\mathrm{Po}^{\mathrm{x}} + {}^{\phantom{+}4}_{+2}\mathrm{He} \]

In the above equation, the values of x and y are:

Options

• x = 220, y = 84

• x = 218, y = 84

• x = 218, y = 82

• none of these

Answer 1

x = 218, y = 84

Explanation:

In alpha decay, the nucleus loses an alpha particle, which is a helium nucleus. So the mass number decreases by 4 and the atomic number decreases by 2. Thus x = 222 − 4 = 218 and y = 86 − 2 = 84.