The decay of a radioactive elemenet is described by the equation A = Ao.e^(-kt) where A is the amount at time t, Ao is the amount at time zero, and k is the decay constant. Determine Ao and the decay constant K Please show the working you did to achieve the answer (formulas, short hand notation) would be helpful so I can see where you are coming from. Solution Ao=amount at time t=0 so Ao=45.3 gm now at t=0.05 45.3*exp(-0.05k)=30.4 so k=7.9772 year^(-1) .