1. The problem statement, all variables and given/known data Hi, The question itself doesnt sound too complicated i some-how got the asnwer,just wondering if its correct or not. Question is:A radioactuve isotope wuith a half-life of 1.6x10^5 s disintegrates to form a stable product.A pure sample of 'x' is prepared with an initial activity of 25000Bq. Caclulate the activity of the sample after week one. 2. Relevant equations A= Ao e^-lamdba (t) T(1/2)= Ln2 /lamda. 3. The attempt at a solution I used initial activity as 25k bq now i thought activity to be in /s? i dont know here is what i've done. A= Ao e^-lamdba (t) LnA = LnA0 - (lamda)x T LnA = ln(25000)-(4.33x10^-6 x 604.8x10^3) A = 1822. <--- would the units be in s^-1? Again thanks for your input =}.