Which type of radiation can be blocked by clothing or aluminum foil?

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

Answer: (D)

The correct choice is that beta particles can be effectively blocked by clothing or aluminum foil. Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive decay. Because they are relatively light and less penetrating compared to other forms of radiation, simple barriers such as clothing and thin layers of materials like aluminum foil can absorb or deflect them, providing adequate protection.

In contrast, alpha particles are much larger and are unable to penetrate the outer layer of skin, which is why they pose a minimal danger unless ingested or inhaled. Gamma rays, being highly penetrating electromagnetic radiation, require much denser materials like lead or thick concrete to shield against them effectively. Neutron particles also require specialized shielding materials, such as water or polyethylene, for adequate protection due to their ability to penetrate materials much more effectively than beta particles. Thus, the ability of clothing and aluminum foil to block beta particles specifically highlights their relative vulnerability compared to other radiation types.