Which type of radiation has the highest penetrating power?

Gamma rays have the highest penetrating power among the types of radiation listed. They are electromagnetic waves with high energy and short wavelengths, which allows them to penetrate materials much more effectively than alpha or beta particles.

Alpha particles are relatively heavy and positively charged, meaning they are heavily affected by electromagnetic forces and can be easily stopped by a sheet of paper or even the outer layers of human skin. Beta particles, which are electrons or positrons, have greater penetrating power than alpha particles and can pass through paper but are generally stopped by plastic or a few millimeters of aluminum.

However, gamma rays, due to their lack of mass and charge, can travel considerable distances and require dense materials such as lead or several centimeters of concrete to attenuate their intensity effectively. This property makes gamma radiation particularly concerning in radiation protection and safety protocols, as it poses a higher risk in terms of deeper tissue penetration and potential biological effects.