Which type of radiation can be stopped by a sheet of paper?

Which type of radiation can be stopped by a sheet of paper?

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

Answer: (B)

The shielding behavior here hinges on how far different types of radiation can penetrate matter. Alpha radiation is a heavy, positively charged helium nucleus with very low penetrating power. Because it interacts strongly with matter, it loses energy quickly and can be stopped by something as thin as a sheet of paper (and even the outer layer of skin provides protection). The other types—beta particles, gamma rays, and neutrons—have greater penetrating capabilities and require more substantial shielding: beta needs plastic or light metal, gamma needs dense materials like lead or thick concrete, and neutrons are slowed or captured best by hydrogen-rich substances. So a sheet of paper stopping the radiation points to alpha as the correct type.

The shielding behavior here hinges on how far different types of radiation can penetrate matter. Alpha radiation is a heavy, positively charged helium nucleus with very low penetrating power. Because it interacts strongly with matter, it loses energy quickly and can be stopped by something as thin as a sheet of paper (and even the outer layer of skin provides protection). The other types—beta particles, gamma rays, and neutrons—have greater penetrating capabilities and require more substantial shielding: beta needs plastic or light metal, gamma needs dense materials like lead or thick concrete, and neutrons are slowed or captured best by hydrogen-rich substances. So a sheet of paper stopping the radiation points to alpha as the correct type.