Which type of radiation has a longer range and can penetrate materials more effectively than alpha particles?

Gamma radiation is indeed the correct choice as it has a longer range and the ability to penetrate materials more effectively compared to alpha particles. This is largely due to its nature; gamma radiation consists of high-energy photons that carry no mass and no charge. As a result, they are less likely to interact with matter when passing through, allowing them to travel greater distances and penetrate dense materials, such as lead or concrete, much more effectively than other types of radiation, such as alpha particles, which are limited by their larger mass and positive charge.

In contrast, alpha particles are heavy and charged, making them less penetrating and easily stopped by a sheet of paper or even human skin. Beta radiation, while more penetrating than alpha particles, does not reach the same level of effectiveness as gamma radiation and is generally stopped by a few millimeters of plastic or glass. X-ray radiation, similar to gamma radiation, involves photons; however, gamma rays typically possess higher energy and thus greater penetration capability. Therefore, gamma radiation is recognized for its extensive range and efficacy in penetrating various materials, distinguishing it from the other types mentioned.