Question

When a nucleus with atomic number Z and mass number A undergoes a radioactive decay process

• A. both Z and A will decrease if the process is $\alpha$-decay
• B. Z will decrease but A will not change if the process is ${\beta }^{+}$ - decay
• C. Z will increase but A will not change, if the process is ${\beta }^{-}$- decay
• D. Z and A will remain unchanged if the process is $\gamma$ - decay

Answer 1

The correct option is A both Z and A will decrease if the process is $\alpha$-decay

A

When an alpha particle is emitted from nucleus the nucleus loses two proton and two neutrons. This means the atomic mass number decreased by 4 and the atomic number decreased by 2. So both 3 and A decreases in the the alpha decay process.