Question

multiple - choice question
what can stop alpha particles?
simply a sheet of paper or cloth
only a lead barrier
only a sheet of metal like aluminum or your skin

Explanation:

Alpha particles are relatively large and have low penetration power. A sheet of paper or cloth is sufficient to stop them. Lead barriers are more for stopping gamma rays. A sheet of metal like aluminum or skin is for stopping beta particles.

Answer:

simply a sheet of paper or cloth