Question

The nucleus obtained after $\alpha$ -emission from the nucleus ${}_y{\text{A}}^x$ is

• A. ${}_{y-2}{\text{B}}^{x-2}$
• B. ${}_{y+2}{\text{B}}^{x+4}$
• C. ${}_y{\text{B}}^x$
• D. ${}_{y-2}{\text{B}}^{x-4}$

Answer 1

The correct option is D ${}_{y-2}{\text{B}}^{x-4}$

The emission of an alpha particle from a nucleus reduces the mass number of the nucleus by $4$ and the atomic number by $2$.