At t=0 there are 6 x 1023 radioactive atoms of a substance, which decay with a disintegration constant (k) equal to 0.01/sec. What would be the initial decay rate?

All radioisotopes decay at a rate obeying the universal law of radioactive decay. This law states that the number of radioisotope nuclei within a population of N radioisotope nuclei decaying at any instant, is propoional to N, therefore Rate of decay = k * N (k is the disintegration constant). k =0.01/sec, N =6*1023 Rate of decay = 0.01* 6*1023 = 6*1021 Ref: Radioisotope Thin-Film Powered Microsystems By Rajesh Duggiral, Page 2