Question: how does radiation radiate

Samantha Watson answered on 10 Nov 2016:

Radiation is the emission of a type of energy. The energy can travel as an electromagnetic wave – visible light is a type of electromagnetic wave, there are other types such as radio waves, micro waves, xrays that we can’t see. Alternatively, radiation may be the emission of sub-atomic – really, really, really tiny – particles from material.

Some types of radiation can interact with materials that they pass through (including human tissues) and produce charged particles in the material – this is known as ionisation, and radiation that can do this is known as ionising radiation. Xrays, gamma rays, and alpha and beta particles are types of ionising radiation. Other types of radiation that can’t do this are known as non-ionising radiation and examples of this are normal visible light, ultraviolet light, radiowaves, lasers, and microwaves.

Ionising radiation can be given out from materials (eg uranium) or made by machines (eg xrays). If a material (rather than a machine) gives out radiation it is said to be radioactive.