which type of radiation has the least penetrating power? * gamma beta alpha x - ray

Brief Explanations:

Alpha - radiation consists of large, heavy alpha particles. They interact strongly with matter, losing energy quickly. So, they have the least penetrating power among common types of radiation. Gamma rays and X - rays are high - energy electromagnetic radiation with high penetration. Beta particles are smaller and lighter than alpha particles and can penetrate further.

Answer:

C. alpha