The atomic number of uranium-235 is 92, its half-life is 704 million years and the radioactive decay of l kg of 235u releases 6.7x10^13 j. generally, radioactive material is considered safe after 10 half-lives.

assume that a nuclear powerplant can convert energy from 235u into electricity with an efficiency of 35%, the electrical transmission lines operate at 90% efficiency, and flourescent lights operate at 22% efficiency.
1.) what is the overall efficiency of converting the energy of 235u into flourescent light?
2.) how much energy from 1 kg of 235u is converted into flourescent light?