Some higher-energy ultraviolet (UV) rays are also ionizing. Gamma rays and X-rays aren't the only types of ionizing radiation. Ionizing radiation can also exist in the form of particles, such as protons, neutrons, and alpha and beta particles. Because of their use in medicine, almost everyone has heard of x-rays.
X-rays are similar to gamma rays in that they are photons of pure energy. X-rays and gamma rays have the same basic properties, but they come from different parts of the atom. X-rays are emitted from processes outside the nucleus, but gamma rays originate inside the nucleus. They are also generally lower in energy and, therefore, less penetrating than gamma rays.
X-rays can be produced naturally or by machines that use electricity. The electromagnetic spectrum (EM) is the range of all types of EM radiation. Radiation is energy that travels and spreads as you go. The visible light that comes from a lamp in your house and the radio waves that come from a radio station are two types of electromagnetic radiation.
The other types of electromagnetic radiation that make up the electromagnetic spectrum are microwaves, infrared light, ultraviolet light, X-rays, and gamma rays. X-rays and gamma rays have enough energy so that, during interaction with atoms, they can remove electrons and cause the atom to become charged or ionized. That's why we refer to them as ionizing radiation. When most people talk about radiation, they're referring to ionizing radiation.
Radioactive decay is the emission of energy in the form of ionizing radiationIon. Radiation with so much energy can expel electrons from atoms. Learn about the different types of radiation, how they interact with atoms and how they can affect you. The energy of the radiation shown in the spectrum below increases from left to right as the frequency increases. Radio waves, gamma rays, visible light, and all other parts of the electromagnetic spectrum are electromagnetic radiation.
X-rays and gamma rays can come from natural sources, such as radon gas, radioactive elements from Earth, and cosmic rays that reach Earth from outer space. Radio waves have low-energy photons, microwave photons have slightly more energy than radio waves, infrared photons have even more than visible photons, ultraviolet photons, X-rays and, the most energetic of all, gamma rays. Gamma rays have such penetrating power that it may take several centimeters of dense material such as lead, or even a few feet of concrete to stop them. The EPA's mission in radiation protection is to protect human health and the environment from ionizing radiation that comes from human use of radioactive elements.
The ionizing radiation that is emitted can include alpha particles, alpha particles, a form of particulate ionizing radiation composed of two neutrons and two protons. The way in which these large, heavy particles cause damage makes them more dangerous than other types of radiation. Calculate your annual dose from the most common sources of ionizing radiation with this interactive online dose calculator. For X-rays and gamma rays (and beta particles), the equivalent dose in Sv is the same as the absorbed dose in Gy.
