posted by james on .
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 > gamm 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 > alhpa particles
It is really a bad question. The alpha particles will interact with matter, and have a very short range, and the beta will interact with conductors (metals) and not penetrate them either. So in fact, on lead, both alpha and beta penetration ranges are nil. Of course, Gamma penetrates to a long depth.
In view of this, either answers b or e are correct, technically, for lead. E probably is what your instructor wants as the "correct" answer.
no wonder this question didn't make sense to me.