1. The problem statement, all variables and given/known data A nuclear power station reactor using 235 U (Uranium) as fuel has an output of 107 W. How much uranium is consumed per hour if the overall efficiency is 10%. The 235 U decays by the following reaction: n + 235 U → 144 Nd + 89 Y + (3)(n) + (7)(e-) 2. Relevant equations P = E / time E = mc2 3. The attempt at a solution I started out by finding the change in mass in the reactants and products: mass of reactants = 236.05258 amu mass of products = 235.845131 amu Δ mass = 0.207449 amu I then used E = mc2 to find the energy released from one uranium nuclei: E = (0.207449amu)(1.66054 x 10^-27 kg)(2.9979 x 10^8 m/s)^2 E = 3.096 x 10^-11 J/atom I then found the efficiency of the reactor: efficiency = output/input x 100% 0.10 = output / input input = 10^8 Joules P = E/t E = (10^8 W)(3600s) E = 3.60 x 10^11 J I now know how much energy is inputed into the generator each hour and I know how much energy is released per atom of Uranium. I can find the total number of atoms that undergo this reaction in one hour: 3.60 x 10^11 J / 3.096 x 10^-11 J/atom = 1.16x10^22 atoms I used avogadro's number to find the number of moles (1.16x10^22 atoms) * (1 mol / 6.022x10^23 atoms) = 0.0193 moles I use n = m / M to find the mass in grams: 0.0193 mol * 235.043915 amu = 4.54g It would be great if anyone could check my steps in my solution. The answer is 4.54 g but I just want to make sure my process is correct and maybe if there is another way to get to the same answer. Thanks, I appreciate it!