Question

What is gamma decay?

Answer 1

The gamma decay is a type of radioactivity in which radiations are emitted in the form of gamma rays. Some unstable atomic nuclei emit the energy in the form of photons or small packets of electromagnetic energy of short wavelength resulting in the stabilisation.

Complete answer:
Let us learn about gamma decay in detail;
Gamma decay –
The emission of electromagnetic radiation of short wavelengths having high energy to stabilise the unstable nucleus is known as gamma decay. In short, it is the nucleus’s way of dropping from higher energy level to the lower energy levels due to emission of high energy photons.
The rays (gamma) emitted are of very high energy i.e. of the order of MeV same as that of x-rays; only the difference between them is that the gamma rays come from the nucleus of an atom.
They are present with high energy and can penetrate deeper into biological systems harming them to great extent. Most often, this decay occurs after the atom undergoes other forms of decay but has less ionising capacity so the severity is less.

Note:
There are 3 types of radioactive decay in common;
Alpha decay in which a helium nucleus is emitted (positive; $\alpha -decay$ ).
Beta decay in which electrons are emitted$\left( \beta -decay \right)$ .
Gamma decay in which high energy photons are emitted$\left( \gamma -decay \right)$ .