Final answer:
The penetration power of radiation varies by type; alpha particles are blocked by paper, beta particles require wood, and gamma particles need lead walls for protection.
Step-by-step explanation:
Understanding the penetration power of radiation types is crucial for safety and protection from potential harm. Each type of radiation possesses different capabilities to penetrate materials. Alpha particles have the least penetration power and can be stopped by something as thin as paper. On the other hand, beta particles have a greater penetration power, requiring more substantial material like wood to block them effectively. However, gamma particles trump both alpha and beta particles in terms of penetration power, as they can pass through paper and wood and are only effectively blocked by several inches of dense materials like lead.
When considering wall penetration levels for safety against radiation, you need materials with enough mass and density to counteract the radiation's penetration power. Hence, for alpha particles, a wall of paper would suffice, whereas beta particles would require a wood barrier. For maximal protection from all common types of radiation, including gamma particles, walls with significant lead content are recommended.