1. The problem statement, all variables and given/known data estimate the density of chromium ions in ruby, assuming that the concentration of chromium in ruby is about 0.05% by weight. 2. Relevant equations decay rate = 0.5x10^3 s^-1 answer: density N (sub T)= 1.6x10^19 cm^-3 3. The attempt at a solution density = mass/volume density of ruby = 4.02 g/cm^3 density of chromium = (4.02)(0.05) = .201 g/cm^3 I know that this is wrong! What do I do?