Which type of radiation has large particles with positive electrical charges?

• A. Gamma
• B. X-ray
• C. Alpha
• D. Beta

Answer: (C)

Alpha radiation involves large, positively charged particles. These particles are helium nuclei, consisting of 2 protons and 2 neutrons, so they are heavy and carry a +2 electric charge. That combination makes them extremely ionizing, meaning they release a lot of energy into nearby matter as they pass through. However, because they are bulky and charged, they don’t travel far and can be stopped by a sheet of paper or even the outer layer of skin. This is in contrast to gamma rays and X-rays, which are electromagnetic waves with no mass or charge and can penetrate more deeply, requiring dense shielding like lead. Beta particles are lighter and are electrons (negative charge) that have more penetration than alpha but still can be stopped by plastic or thin metal. So the type with large particles and positive charges is alpha radiation.