Which statement describes Alpha Radiation?

• A. Beta Radiation
• B. Alpha Radiation has mass and weight and can be stopped by a sheet of paper
• C. Gamma Radiation
• D. Neutron Radiation

Answer: (B)

Alpha radiation consists of helium-4 nuclei, which have mass and a positive charge. Because of their mass and charge, these particles interact strongly with matter and lose energy quickly, giving them very low penetrating power. A sheet of paper fully stops them, which is why external exposure is typically not dangerous unless the material emitting them is ingested or inhaled. The statement that describes alpha radiation as having mass and weight and being stoppable by a sheet of paper matches these properties: mass means they have weight in a gravity field, and their low penetrating power is why only a thin barrier is needed to stop them.