Radiation Safety Practice Exam

Which particle has a range of a few feet in the air and can penetrate a sheet of paper but not a thin sheet of aluminum?

1. Alpha particle

2. Beta particle

3. Gamma ray

4. X-ray

The correct answer is: Beta particle

The beta particle is indeed the correct choice because it is a type of radiation resulting from the decay of certain radioactive atoms. Beta particles, which consist of high-energy, high-speed electrons or positrons, have a range in air that typically extends to a few feet depending on their energy level. They possess enough energy to penetrate materials better than alpha particles, which are unable to pass through paper but are stopped by human skin. However, beta particles cannot penetrate materials like a thin sheet of aluminum; typical beta particle energies can be stopped by a few millimeters of aluminum. This characteristic makes them more penetrating than alpha particles, while still being less penetrating than gamma rays or X-rays, which can pass through much thicker materials. The context of beta particle penetration is important in radiation safety, as it informs protective measures needed when dealing with radiation exposure in various environments. Understanding how different types of radiation interact with matter helps in designing proper shielding and safety protocols in any situation involving radioactive materials.