(ii) using equation in 33{axi), estimate the decay constant, which would be suitable for dating 4.2 ga old rock. assume that the rock has roughly equal proporti

(ii) Using equation in 33{aXi), estimate the decay constant, which would be suitable for dating 4.2 Ga old rock. Assume that the rock has roughly equal proportions of parent and daughter atoms at present. Consider ln 2 = 0.693. (3) )Name the radioactive isotopes, which yield 20*Pb, Pb and "Pb. (9)