Which ionizing radiation type has the highest penetration ability?

Gamma radiation possesses the highest penetration ability among the types of ionizing radiation. This is due to its nature as electromagnetic radiation with high energy and no mass, allowing it to travel through materials more effectively than other forms of radiation. Gamma rays can penetrate through skin and several centimeters of lead or concrete, making them particularly hazardous.

In contrast, alpha particles, which consist of two protons and two neutrons, have a low penetration capability and can be stopped by a sheet of paper or even the outer layers of human skin. Beta particles, which are high-energy electrons or positrons, have a greater penetration ability than alpha particles, but are still significantly less penetrative than gamma rays, being stopped by materials like plastic or glass. Neutrons, while being a different type of radiation, can also penetrate materials but not as efficiently as gamma rays; their interaction depends heavily on the material they encounter. Thus, gamma radiation is considered the most penetrating form of ionizing radiation, making it vital to understand its properties for safety and protection in various settings.