Radioactive Decay - Beta Decay

Beta decay

$$X\to Y+e$$

1. A beta particles is an electron emitted from a nucleus.
2. The beta particles are very small and move with very high speed.
3. During a beta decay, a radioactive atom X decay and emits a beta particle ($e$ ).
4. 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. $$n\to p+e$$
5. Therefore proton number increase by 1 and the nucleon number remain unchanged.

Examples of beta decay
$$\begin{array}{l}Th\to Pa+e\\ \\ Pb\to Bi+e\\ \\ Be\to B+e\\ \\ Fe\to Co+e\\ \\ Na\to Mg+e\end{array}$$