Final answer:
Alpha particles can be stopped by paper, beta particles require a metal sheet for blocking, and gamma rays need inches of lead or feet of concrete for adequate shielding.
Step-by-step explanation:
The question pertains to the penetration power of different types of radiation and what materials can stop them. Alpha particles are relatively large and can be stopped by a thin material such as paper. Beta particles are smaller and more penetrating than alpha particles; they can be stopped by denser materials like metal, specifically a thin sheet of aluminum. Gamma rays, however, are highly penetrating and require several inches of a dense material like lead or more than a foot of concrete for absorption and blocking.
It's important to note that while alpha particles can be blocked by something as simple as paper, they can be quite hazardous if ingenerated or inhaled. Similarly, beta particles represent a danger when the beta-emitting source is inside the body. Gamma rays can penetrate deeply into most objects and require substantial shielding.