Which materials can beta particles penetrate?

Beta particles are high-energy, high-speed electrons or positrons emitted during radioactive decay. Given their relatively small mass and charge, they have greater penetrating power compared to alpha particles but less than gamma rays.

The correct answer indicates that beta particles can penetrate a few centimeters of lead and a few meters of air. This is due to their ability to interact with matter primarily through ionization. In gases, such as air, beta particles can travel several meters before losing their energy, while in denser materials like lead, they can penetrate a few centimeters before being absorbed.

The other options suggest limitations on penetration that do not accurately reflect the behavior of beta particles. For example, they do not solely penetrate air—while they do penetrate air effectively, beta particles can also penetrate through substances like aluminum foil without being completely absorbed. Each material has a specific thickness at which beta particles can still be detected, and lead as a dense material illustrates that beta particles have significant penetrating capability.