Question

Alkaline earth metal is radioactive. It and its daughter element decay by emitting 3 $\alpha$-particles in succession. In what group should the resulting element be formed?

• A. 13
• B. 14
• C. 12
• D. 10

Answer 1

The correct option is B 14

$3\alpha \to 3{}_{2}H{e}^4\to$ Atomic number decreases by 6.
$\to$ Loss of 6 p and 6 n.

The resulting element will be in ${14}^{th}$ group.