Concept:The penetrating power of radiation increases from alpha to beta to gamma.
Explanation:Alpha particles are the least penetrating and are stopped by a sheet of paper.
Beta particles can pass through paper but are stopped by a thin sheet of aluminium.
Gamma rays are the most penetrating and require concrete or lead for effective shielding.
From the diagram, X is the radiation that is not stopped by the shields, so X is a
γ-ray.
Y is stopped first, so Y is an
α-particle.
Z passes through the paper but is stopped afterwards, so Z is a
β-particle.
Answer:X =
γ-ray; Y =
α-particle; Z =
β-particle.
