A 1000 MW fission reactor consumes half of its fuel in 5.00 y. How much`""_(92)^(235)` U did it contain initially? Assume that the reactor operates 80% of the time, that all the energy generated arises from the fission of `""_(92)^(235)` U and that this nuclide is consumed only by the fission process.

In a nuclear reactor the chain reaction is carried out under controlled conditions. Average energy of a neutron produced in fission of (^235_92)U nucleus is ..

Initially the earth was a fire-ball, slowly it has cooled to form earth crust and its different layers. At the beginning ""_(92)^(238)U was present and no ""_(82)^(206) Pb was there. With the passage of time, uranium decayed to ""_(82)^(206)Pb The decay process is : ""_(92)^(238)U underset((x alpha, y beta))to ""_(82)^(206)Pb , t_(1//2) of ""^(238)U = 4.5 xx 10^(9) yrs A sample of rock from south America contains equal number of atoms of ""^(238)U and ""^(206)Pb . The age of the rock will be :