There are three main types of nuclear radiation: alpha particles, beta particles, and gamma rays.
1. Alpha particles are made up of two protons and two neutrons and are essentially helium nuclei. They have a positive charge and are relatively large and heavy, which means they can be stopped by a piece of paper or the outer layer of skin.
2. Beta particles are high-energy electrons that are emitted from the nucleus of an atom. They have a negative charge and are much smaller than alpha particles, which means they can penetrate through the skin and into the body.
3. Gamma rays are high-energy electromagnetic radiation, similar to X-rays. They are emitted from the nucleus of an atom and have no charge. They are extremely penetrating and can travel long distances through air and most materials, including the human body.