There are three types of radiation. Gamma rays, alpha particles, and beta particles. An alpha particle is a high energy, positively charged particle given off by the nucleus of a radioactive atom. An alpha particle has two protons, and two neutrons. An alpha particle weighs at least 7000 times more than a beta particle.
Alpha particles are only able to travel short distances because of their size.
A beta particle is an electron that is given off when the nucleus of a radioactive atom undergoes a nuclear transformation. Beta particles are usually negatively charged. They are formed when a neutron converts to a proton. A beta particles high energy causes it to be able to travel very far through solid matter. Its energy is measured by how far it can travel into a certain substance.