In 5.00 half-lives, the radioactivity is reduced by
21 0 0312 100 3 12..%500.
cm ==#- Which of the following choices correctly describes the decreasing ability of the radiation
to penetrate a sheet of lead that is 3 inches thick?
A. alpha particles > beta particles > gamma rays
B. gamma rays > alpha particles > beta particles
C. alpha particles > gamma rays > beta particles
D. beta particles > alpha particles > gamma rays
E. gamma rays > beta particles > alpha particlesAnswer: E
Gamma rays (γ) have high penetrating power and are not deflected by electric or magnetic
fields. Beta particles (β) have a lower ionizing power and greater penetrating power than alpha
particles (α).
Part II: Specific Topics