Also called radioactive substance. As used in the brachytherapy treatment of cancer, a radioactive material is sealed inside a seed or pellet and placed inside the body, in or near a tumor. The radiat [..]

A material whose nuclei spontaneously give off nuclear radiation. Naturally radioactive materials (found in the earth's crust) give off alpha, beta, or gamma particles. Alpha particles are Helium [..]

Any compound or element which may emit any or all of the following; alpha and beta particles, electrons, photons neutrons and gamma, and all other emissions which produce ionization directly or indire [..]

Any natural or artificial material whether in the solid or liquid form, or in the form of a gas or vapour, that exhibits radioactivity. For regulatory purposes, radioactive substances may be defined as radioactive material that has an activity level of 100 becquerels per gram or greater.

A material whose nuclei spontaneously give off nuclear radiation. Naturally radioactive materials (found in the earth's crust) give off alpha, beta, or gamma particles. Alpha particles are Helium [..]

material that contains unstable (radioactive) atoms that give off radiation as they decay. Radioactivity: the process of spontaneous transformation of the nucleus, generally with the emission of alpha [..]

Radioactive Material is any material that contains radioactive atoms.

Is a physical material that emits ionizing (electrically charged atoms) radiation.

Radioactive material is material that contains radioactivity and thus emits ionizing radiation. It may be material that contains natural radioactivity from the environment or a material that may have [..]

A radioactive material is any substance which gives off radiation.