Physics – 5.2.5 Safety precautions | e-Consult

There are three main types of ionising nuclear radiation: alpha particles, beta particles, and gamma rays. They differ significantly in their penetrating power:

Alpha particles are relatively heavy and carry a positive charge. They have a low penetrating power and can be stopped by a sheet of paper or even a few centimetres of air. However, if alpha particles enter the body, their high ionization potential can cause significant damage to tissues they pass through.

Beta particles are electrons or positrons. They have a greater penetrating power than alpha particles, able to penetrate a few millimetres of tissue. They can be stopped by a thin sheet of metal like aluminium.

Gamma rays are high-energy electromagnetic radiation. They have the highest penetrating power of the three types and can pass through a significant thickness of materials, such as lead or concrete. They are particularly dangerous because they can penetrate the body and damage cells throughout.

The difference in penetrating power dictates the level of protection required. Alpha particles require only superficial shielding (e.g., a sheet of paper). Beta particles require more substantial shielding (e.g., aluminium). Gamma rays require dense shielding materials like lead or concrete to effectively absorb them.