ionising radiation – radiation capable of removing electrons from atoms

(pronounced ai-uh-nye-zing)

To remember the meaning of ionising radiation, use the following mnemonic:

Iron man skates on ice and sings (ionising) while removing electronic (removing electrons) robots.

Ionising radiation is a type of high energy radiation that has enough energy to remove or knock out electrons from other atoms or molecules, creating charged particles called ions, which can cause significant damage to living cells and materials. This radiation comes in several forms including alpha particles, beta particles, gamma rays, and x-rays. 

Alpha particles are the most heavily ionising but least penetrating form of radiation, stopped by paper or skin, while beta particles are moderately ionising and penetrating, stopped by a few millimetres of aluminium, and gamma rays are weakly ionising but highly penetrating, requiring thick lead to block them effectively. 

Ionising radiation can damage living tissue by destroying cells and breaking chemical bonds within DNA, which can cause mutations, cancer and even acute radiation sickness with enough exposure. In a controlled environment, ionising radiation can be used for positive purposes, such as sterilising medical equipment, or killing cancer cells in a radiotherapy procedure.