Question

In radioactive decay ${}_{90}T{h}^{234}\to {}_{92}T{h}^{234}$ the number of $\alpha$ and $\beta$ - particles emitted respectively are

• A. $1,2$
• B. $2,0$
• C. $0,2$
• D. $2,1$

Answer 1

The correct option is C $0,2$

There is no change in mass number, hence no $\alpha$ particles are emitted.
Atomic number increased by 2 $\Rightarrow$ 2 $\beta$ particles are emitted.