Associate Safety Professional Practice Exam

Which type of radiation can be effectively shielded by materials such as paper and clothing?

1. Alpha rays

2. Beta radiation

3. Gamma rays

4. X-rays

The correct answer is: Alpha rays

Alpha rays are a type of radiation that consists of alpha particles, which are relatively heavy and positively charged. Because of their mass and charge, alpha particles have very low penetration power. They can be stopped by just a few centimeters of air, or even by materials like paper and clothing. This makes alpha radiation significantly less hazardous to external exposure compared to other types of radiation. In contrast, beta radiation, gamma rays, and X-rays have much greater penetration capabilities. Beta particles can penetrate further, requiring a thicker material like plastic or aluminum for effective shielding. Gamma rays and X-rays, being high-energy electromagnetic radiation, are even more challenging to shield against and require dense materials such as lead or concrete to significantly reduce exposure. Thus, the effectiveness of paper and clothing as shielding materials is specific to alpha rays due to their limited penetration ability.