Which shielding material is typically sufficient to block alpha particles?

Which shielding material is typically sufficient to block alpha particles?

• A. Paper
• B. Lead
• C. Plastic
• D. Aluminum foil

Answer: (A)

Alpha particles have very low penetrating power because they are relatively heavy and carry a +2 charge, so they interact strongly with matter and lose energy quickly. This means they can be stopped by a very thin barrier. A sheet of paper is enough to stop most alpha radiation, making it the typical shielding choice for externally encountered sources. Heavier shielding like lead isn’t needed for alpha particles, and while plastic or aluminum foil would also block them, paper is the simplest, sufficient barrier.

Alpha particles have very low penetrating power because they are relatively heavy and carry a +2 charge, so they interact strongly with matter and lose energy quickly. This means they can be stopped by a very thin barrier. A sheet of paper is enough to stop most alpha radiation, making it the typical shielding choice for externally encountered sources. Heavier shielding like lead isn’t needed for alpha particles, and while plastic or aluminum foil would also block them, paper is the simplest, sufficient barrier.