It is the fundamental building block of elements. The number assigned to each element on the basis of the number of protons found in the element's nucleus. Approximately the sum of the number of protons and neutrons found in the nucleus of an atom. The radiation of man's natural environment originating primarily from the naturally radioactive elements of the earth and from the cosmic rays. The term may also mean radiation extraneous to an experiment.
Beta particles are more penatrating than alpha particles but less than gamma rays or x-rays.
Contamination Radioactive material deposited or dispersed in materials or places where it is not wanted. Cow A radioisotope generator system. The basic unit used to describe the intensity of radioactivity in a sample of material. One curie equals thirty-seven billion disinteegrations per second, or approximately the radioactivity of one gram of radium. The change of one radioactive nuclide into a different nuclide by the spontaneous emission of alpha, beta, or gamma rays, or by electron capture.