Gamma Rays & X-rays

Gamma rays and X-rays are waves of energy that travel at the speed of light. Unlike alpha and beta particles, gamma rays and X-rays consist of photons rather than particles. Photons have no mass or charge and travel in straight lines.

The waves of gamma rays and X-rays have considerable range in air and greater penetrating power compared to either alpha or beta particles. The most significant difference between gamma rays and X-rays is where they are located in an atom. Gamma rays originate from the nucleus of an atom, while X-rays come from the electron cloud.

Both gamma rays and X-rays can penetrate deeply into the human body. Higher energy gamma rays and X-rays penetrate deeper into the body than lower energy gamma rays and X-rays. A common radionuclide that emits gamma rays is technetium-99m, a radioactive material used in nuclear medicine. X-rays are generally produced by machines used in medicine and industry. Gamma rays and X-rays can be effectively blocked by lead or other heavy materials.

To learn more about Ionizing Radiation visit our Ionizing Radiation Safety Online Training web page.