Alpha, beta, and gamma radiations are three types of ionizing radiation produced by radioactive substances.

Alpha Radiation

Alpha radiation consists of alpha particles, which are composed of two protons and two neutrons—essentially forming a helium nucleus. These particles carry a positive charge and are relatively large, making them highly ionizing but less penetrating. Alpha particles can be effectively stopped by a sheet of paper or just a few centimeters of air. They are typically emitted by heavy, proton-rich unstable nuclei. During the process of alpha decay, a nucleus transforms into a new element, decreasing its atomic number by $2$ and its atomic mass by $4$.

Beta Radiation

In contrast, beta radiation consists of high-speed electrons (known as beta-minus) or positrons (known as beta-plus) that are ejected from the nucleus. Beta-minus decay occurs when a neutron within the nucleus is converted into a proton, an electron, and an electron antineutrino. Conversely, beta-plus decay involves the transformation of a proton into a neutron, a positron, and a neutrino. Beta particles are smaller and travel faster than alpha particles, which makes them less ionizing but more penetrating; they can be stopped by a few millimeters of aluminum.

Gamma Radiation

Gamma radiation is a form of electromagnetic radiation, similar to X-rays but with higher energy. It is emitted from the nucleus during radioactive decay or nuclear reactions. Unlike alpha and beta particles, gamma rays are not particles but rather waves; they carry no charge. This characteristic makes them the least ionizing yet the most penetrating type of radiation, capable of passing through several centimeters of lead or meters of concrete. Gamma decay often follows alpha or beta decay, occurring when the remaining nucleus is left in an excited state and requires energy loss.

Summary

In summary, alpha, beta, and gamma radiations are all byproducts of radioactive decay, but they differ significantly in their composition, charge, ionizing ability, and penetrating power. Understanding these differences is essential for effective radiation safety management and for harnessing the potential of nuclear energy.