Question

An element ${}_Z^A\text{M}$ undergoes an $\alpha$-emission followed by two successive $\beta$-emission. The element formed is ${}_Z^{A-4}\text{M}$.

• A. True
• B. False

Answer 1

The correct option is A True

We know that, during an ⍺-emission, the atomic no. gets reduced by 2 and the mass no. gets reduced by 4 whereas, in a β-emission, the atomic no. is increased by 1 and there is no change in the mass no.

Thus, after one ⍺-emission followed by two successive β-emissions, the mass no. is reduced by 4 and the atomic no. remains the same as α-emission reduces the atomic no. by 2 but two successive β-emissions again increases the atomic no. by 2.

Hence, the given statement is True.