Which type of radiation can be stopped by paper or skin?

• A. Beta particles
• B. Alpha particles
• C. Gamma rays
• D. Neutrons

Answer: (B)

Alpha particles are a type of radiation that consists of two protons and two neutrons, essentially making them helium nuclei. Due to their relatively large mass and positive charge, alpha particles have a very short range and low penetration power. They can be effectively stopped by materials such as paper or even the outer layer of human skin. This characteristic makes alpha radiation less hazardous compared to other types of radiation when it comes to external exposure. However, alpha emitters can be dangerous if ingested or inhaled, as they can cause significant damage to biological tissues from within. Understanding this property is crucial for effectively managing radiation safety and potential hazards in hazardous materials situations.