Which type of radiation has no mass, no charge, and is highly penetrating?

• A. Beta
• B. Gamma
• C. Alpha
• D. Xrays

Answer: (B)

No mass and no electric charge describe electromagnetic radiation, which includes gamma rays. Gamma rays are produced by nuclear transitions and have very high energy, allowing them to pass through thick materials with only gradual attenuation. Among the options, gamma rays fit these traits best: they carry no mass or charge and are highly penetrating. X-rays are also massless and uncharged, but gamma rays typically have higher energy and penetrate more deeply, which is why gamma radiation is described as highly penetrating. The other options involve particles with mass and/or electric charge (alpha and beta particles), which makes them less penetrating.