[问答题]
The plutonium isotope
2wmar u *ilxvp2e.5:yro5,g pd ng4)r40hzrm$^{238}_{94}Pu undergoes alpha decay.
1.Define isotope.
2.Rewrite this decay equation, filling in any missing information.
3.Plutonium undergoes a decay series. The graph below shows a part of this decay series.
(1)One type of decay
cannot be represented on this diagram. Outline this type of decay and justify your answer.
(2)State the type of decay of $^{230}_{90}Th$ that is represented on the diagram above. Justify your answer.
(3)Isotope X undergoes an alpha decay followed by a beta minus decay to produce isotope Y. Label the position of isotope Y on the diagram.
4.Compare the penetrating powers of alpha, beta and gamma radiation.
