7.4 understand that alpha and beta particles and gamma rays are ionising radiations emitted from unstable nuclei in a random process
When a unstable nuclei decay they give out ionising radiation. Ionising radiation causes atom to gain or lose electrons to form ions. Basically there are three types of ionizing radiation: alpha, beat and gamma.
Alpha radiation: Alpha radiation consists of fast-moving helium nucleus.
Beta radiation: Beta radiation consists of fast-moving electron.
Gamma rays: Gamma ray is an electromagnetic wave.