Which radiation can be stopped by aluminum foil?

Alpha radiation can indeed be stopped by materials such as aluminum foil, making it a suitable choice. Alpha particles are relatively large and positively charged, consisting of two protons and two neutrons. Due to their size and mass, they have limited penetration abilities and can be easily blocked by even a sheet of paper or a thin layer of aluminum foil.

When considering the other types of radiation, gamma radiation consists of high-energy photons and is much more penetrating than alpha particles, requiring dense materials like lead or several centimeters of concrete to effectively shield against it. Beta radiation, which consists of electrons or positrons, can penetrate further than alpha radiation but can be stopped by materials like plastic or glass; however, it typically requires more than just aluminum foil for complete protection in all scenarios. Ultraviolet radiation is electromagnetic radiation, which can be absorbed by various materials, but aluminum foil is more commonly associated with blocking specifics related to alpha particles.

In summary, aluminum foil's effectiveness in stopping alpha radiation underscores the characteristics of alpha particles as relatively easily obstructed by light shielding materials.