What type of radiation is most penetrative and can pass through the human body?

Gamma rays are high-energy electromagnetic radiation that can penetrate various materials, including the human body, more effectively than other types of radiation. They have no mass and no electric charge, allowing them to travel at the speed of light and penetrate deeply into matter. Gamma rays are produced by nuclear reactions and certain types of radioactive decay, making them highly energetic and capable of passing through human tissues and organs with relative ease.

In contrast, alpha particles are large and positively charged, which limits their penetrative ability significantly; they can be stopped by a sheet of paper or even the outer layer of human skin. Beta particles, while more penetrative than alpha particles, still have limitations as they can be stopped by a few millimeters of plastic or glass. Neutrons can penetrate materials to some extent, but their interaction with biological tissues is complex and they are less penetrating than gamma rays in general applications. This is why gamma rays are considered the most penetrative type of radiation listed.