Which of the following materials is effective at shielding beta radiation?

Plastic and aluminum are effective materials for shielding beta radiation because they have low atomic numbers and are relatively light, which allows them to effectively absorb the high-energy electrons that make up beta radiation. When beta particles interact with materials, they can lose energy and ultimately come to a stop. The effectiveness of a shield against beta radiation depends largely on the thickness and density of the material.

Plastic, especially in the form of polyethylene, is commonly used for radiation shielding because it can effectively slow down and capture beta particles. Aluminum, being a light metal, also serves as a good barrier since it can prevent beta particles from penetrating deeper. In many applications, combining both plastic and aluminum can optimize the shielding by providing a sufficient thickness to absorb beta radiation without being overly heavy or impractical.

While skin does provide some level of protection against beta radiation, it can be penetrated particularly by high-energy beta particles. Lead is more commonly used for gamma radiation shielding due to its high density and atomic weight, making it less effective against beta particles. Concrete can provide some shielding, but it is generally not as effective or efficient for beta radiation as lighter materials like plastic and aluminum. Therefore, options that do not combine the appropriate qualities of thickness and density needed to stop beta radiation would