Beta Particle

A beta particle ($\beta$) is a high-speed electron emitted from the nucleus. It is created when a neutron converts into a proton.

Beta particles have moderate ionising power (less than alpha, more than gamma) and moderate penetrating power (stopped by a few millimetres of aluminium).

In beta decay, the nucleon number stays the same but the proton number increases by 1.

${}^A_Z X \rightarrow {}^A_{Z+1} Y + {}^0_{-1} \beta$