Which radiation type has greater penetration ability?

Gamma radiation possesses the greatest penetration ability among the various types of radiation listed. This characteristic is due to its nature as highly energetic electromagnetic radiation. Gamma rays can penetrate through most materials, including human tissue, with relative ease because they have no mass and no charge, which allows them to travel long distances without being easily absorbed or scattered.

Alpha particles, which are heavier and positively charged, have limited penetration power and can be stopped by a sheet of paper or the outer layer of skin. Beta particles, being lighter and negatively charged, can penetrate materials more effectively than alpha particles but still fall short compared to gamma rays. X-rays, while also a form of electromagnetic radiation capable of penetrating materials, typically have lower energy than gamma rays and consequently are less penetrating.

In summary, the high energy and lack of charge associated with gamma radiation enable it to penetrate materials much more effectively than alpha particles, beta particles, or even X-rays, making it the correct answer.