The rest mass of a 200-keV photon is equal to the rest mass of a 200-keV electron:
True
False
If Na is Avogadro's number, which of the following expressions will yield the activity of a uniform sample with atomic number Z, mass number A, density P, number of radioactive atoms N, total interaction coefficient λ, and half-life T1/2?
(a) A = NλT1/2
(b) A = ZλP
(c) A = Nλln2
(d) A = HλT1/2