1. Radioactive elements decay via first-order kinetics. Consider a certain type of nucleus that has a rateconstant of 2.6✕10–2 h–1. A sample contains 6.5✕108radioactive nuclides. Calculate the time required for 61% of the nuclides to decompose.
(A) 1.9 ✕101 h;
(B) 1.6✕10^{1 h;
(C) 0.8✕101 h;
(D) 3.6✕101 h;
(E) 2.4✕101 h}