Alpha Decay
- During an alpha decay, a radioactive atom X decay and emits an alpha particle (H42e ).
- Atom X losses 2 neutron and 2 proton and become atom Y.

Example

Beta decay

- A beta particles is an electron emitted from a nucleus.
- The beta particles are very small and move with very high speed.
- During a beta decay, a radioactive atom X decay and emits a beta particle (e0−1 ).
- One of the neutron is disintegrated to become proton and electron. The electron is emitted out from the nucleus whereas the proton stay in the nucleus.
- Therefore proton number increase by 1 and the nucleon number remain unchanged.


Gamma Emission
Gamma emission causes no change in nucleon number or proton number.