Physics - Modern Physics Question with Solution | TestHub

As we know due to $\alpha$-decay atomic number decreases by $2$ and mass no. decreases by $4 .$ And due to ${\beta }^{-}$decay mass no. remain unchanged and atomic no. increases by $1$ And due to ${\beta }^{+}$decay mass no. remain unchanged but atomic no. decreases by $1$.

So, option $\left(3\right)$ is correct option.