Which of the following statements is correct?

Step 1: Analyze the question We need to pick the statement that correctly describes the mass and penetrating power of alpha particles, beta particles and gamma rays.

Step 2: Recall the concepts

| Radiation | Nature | Mass | Penetrating power | |---|---|---|---| | Alpha (α) | Helium nucleus (2 protons + 2 neutrons) | Large (about 4 u) | Low, stopped by paper or a few cm of air | | Beta (β) | Fast-moving electron | Very small (about 1/1840 u) | Moderate, stopped by a few mm of aluminium | | Gamma (γ) | Electromagnetic wave (photon) | None (zero rest mass) | Very high, reduced only by thick lead or concrete |

Step 3: Check each option

• A. Alpha particles do have a large mass, but their penetrating power is low, not high. ❌
• B. Alpha particles do have a low penetrating power, but their mass is large compared with beta particles, not small. ❌
• C. Beta particles have a very small mass, but not zero, and their penetrating power is moderate. ❌
• D. Beta particles have a small mass, not a large one. ❌
• E. Gamma rays are electromagnetic radiation with no mass, and they have a very high penetrating power. ✅

Step 4: Answer The correct statement is E.

Tip: Remember the order of penetrating power as α < β < γ, which is paper, then aluminium, then lead. Ionizing power runs the opposite way: α > β > γ. Also, only gamma rays are massless because they are waves (photons), while α and β are particles with mass.