Types of Radioactivity
This refers to when unstable nuclei decompose in nature.
Note: Nuclei of protium contain only a proton. The proton and neutrons are referred to as nucleons/nucleus.
There are three major types of natural radioactivity:
i. Alpha Radiation (α-ray):
Alpha radiation consists of a stream of positively charged particles called alpha particles, which have an atomic mass of 4 and a charge of +2 (A helium nucleus). When alpha’s particles are ejected from the nucleus, the mass number of the nucleus decreases by four units and the atomic number decreases by two units.
ii. Beta Radiation( β-ray):
This is a stream of electrons, called beta particles. When a beta particle is ejected, a neutron in the nucleus is converted to a proton, the mass number of the nucleus is unchanged but the atomic number increases by one unit.
iii. Gamma Radiation (Y-ray):
Gamma rays are high energy protons that result from an energy change within the atomic nucleus. Gamma emission changes neither the atomic number nor atomic mass. Alpha and Beta emissions are often accompanied by Gama emissions as an excited nucleus drops to a lower and more stable energy state.