Glossary - R

Radiation

Energy given off by atoms when they are moving or changing state. It can take the form of electromagnetic waves, such as heat, light, X-rays, or gamma rays, or streams of particles such as alpha particles, beta particles, neutrons or protons.

Source: AECL

Radioactive Dating

A technique for estimating the age of an object by measuring the concentrations of various radioisotopes in it.

Source: AECL

Radioactivity

The emission of alpha particles, beta particles, neutrons and gamma or x-radiation from the disintegration of an atomic nucleus.

Source: AECL

Radioisotope

Atoms of chemical elements may have many isotopes (different forms) with different atomic numbers and different atomic weights. If an isotope is radioactive, it is sometimes referred to as a radioisotope or a radionuclide.

Source: AECL

Radionuclide

An unstable isotope of an element that decays or disintegrates spontaneously, emitting radiation.

Source: AECL