Which statement about alpha radiation is true?

Which statement about alpha radiation is true?

• A. It is highly penetrating
• B. It travels long distances in air
• C. It has no shielding requirements
• D. It is shielded by paper or clothing and hazard if inhaled or ingested

Answer: (D)

Alpha radiation consists of heavy, positively charged helium nuclei. Because of their large mass and charge, they interact strongly with matter and lose energy quickly, giving them a very short range. That means they are readily stopped by a sheet of paper or even by clothing, so external exposure is easily shielded. However, if alpha-emitting materials are inhaled or ingested, the particles can deposit in the lungs or other tissues and cause substantial internal damage due to high ionization in a small, localized area. This combination—shielding by simple barriers like paper or clothing and significant hazard if inhaled or ingested—is why that statement is true.

Alpha radiation consists of heavy, positively charged helium nuclei. Because of their large mass and charge, they interact strongly with matter and lose energy quickly, giving them a very short range. That means they are readily stopped by a sheet of paper or even by clothing, so external exposure is easily shielded. However, if alpha-emitting materials are inhaled or ingested, the particles can deposit in the lungs or other tissues and cause substantial internal damage due to high ionization in a small, localized area. This combination—shielding by simple barriers like paper or clothing and significant hazard if inhaled or ingested—is why that statement is true.