What type of radiation is most effectively shielded by common materials?

Alpha radiation is most effectively shielded by common materials due to its particular characteristics. Alpha particles are relatively large, composed of two protons and two neutrons, which makes them positively charged and heavy compared to other types of radiation. Consequently, alpha particles have low penetration power and can be stopped by a sheet of paper, clothing, or even the outer layer of human skin.

This characteristic of alpha particles allows them to be effectively shielded without the need for complex materials or heavy-duty barriers. In practical terms, this means that everyday items can provide sufficient protection against alpha radiation, making it less of a concern in terms of barriers compared to other types, such as beta particles, gamma rays, and X-rays, which require denser materials for effective shielding.