The nuclei of the atoms in some elements are unstable and emit radiation. The radiation can be of three types - alpha radiation, beta radiation and gamma radiation.

All types of radiation become less intense as they ... The thicker the substance, the more the radiation is absorbed. Alpha, beta and gamma radiations penetrate materials in different ways.

Potassium 40, the main source of radioactivity in our bodies, has a half-life of 1.42 billion years. Types of Radiation The term "radiation" is very broad, and includes such things as light and radio ...