Ionizing radiation

Ionizing radiation is a type of processionals that affects the atoms and molecules inside the human body. Some atoms are unstable and want to stabilize their nucleus. When the nucleus changes it emits such a high level of energy that it makes it possible for some of the atom's tightly bound electrons to get removed. After the electrons are removed from the atom the atom changes so that it is charged, or ionized.

Alpha, Beta and Gamma are the three most common types of ionizing radiation, and can be emitted as either waves or particles. Alpha travels rather slowly compared to other forms of radiation, and as it interacts with atoms and electrons it looses its energy. This makes alpha radiation more or less no threat to humans, unless it is released inside of the human body, if so it can do big damage causing ionization of atoms inside the body. Beta radiation travel faster and longer than alpha radiation, and can therefore cause more damage than alpha radiation on the outside our bodies, depending on their speed. As an example beta particles can cause beta burns, which are severe skin burns, if they are in fallout. Gamma radiation is the most damaging type of radiation out of the three mentioned above, and can easily penetrate through our skin. How far into our body it penetrates depends on its energy, some gamma rays can penetrate entirely through the body, ionizing thousands of atoms and cause major damage.

https://www.who.int/ionizing_radiation/about/what_is_ir/en/

https://ehss.energy.gov/ohre/roadmap/achre/intro_9_1.html