Which type of radiation has the greatest penetrating power?

Gamma rays possess the greatest penetrating power among the types of radiation listed. This is due to their nature as high-energy electromagnetic waves. Unlike alpha particles, which are heavy and positively charged, and beta particles, which are lighter and more interactive, gamma rays have no mass and no charge, allowing them to pass through materials with much less interaction.

Because gamma rays are highly energetic, they can penetrate heavy materials such as lead and concrete, which are typically used as shields against radiation. They can even penetrate human tissue to a certain extent, making them particularly concerning in radiation safety contexts.

X-rays, while also high-energy electromagnetic radiation, have slightly lower energy than gamma rays and thus less penetrating power. This characteristic is critical in medical imaging but does not match the penetrative efficacy of gamma rays. Understanding these distinctions helps in evaluating the safety and shielding requirements in environments where various types of radiation are present.