Question

Two waste products from nuclear reactors are strontium $_{38}^{90}\textrm{Sr}$ (T_1/2 = 28.5 yr) and cesium $_{55}^{134}\textrm{Cs}$ (T_1/2 = 2.06 yr). These two species are present initially in a ratio of N₀,_Sr/N₀,_Cs = 7.80 x 10^-3. What is the ratio N_Sr/N_Cs fifteen years later?

Answer 1