(a) Identify the unknown in each of the following radiouctive deeay and the type of the radioactive decay: i. 92238U90234Th+(?)(5 points) ii. T(2)++D(5 points ) (b) The radioactive decay law can be written as N(t)=N0eC1t=N0et/C2=N0(21)t/C2 Among C1,C2, and C3, which is the decay constant? which is the mean lifetime? which is the half life? ( 5 points) Given a decay constant, how do we find the half life? ( 5 points)