試題詳解

6. Choose the correct statement for half-life:
(I) the time for a sample to decay completely.
(II) constant for a given radioisotope.
(III) the time required for half of a sample to decay.
(IV) inversely proportional to the decay constant.
(A) I and II
(B) I, II, and III
(C) I and III
(D) I, III, and IV
(E) II, II, and IV