Suppose you are a member of a scientific team in a nuclear power plant. You would need to be able to predict how much energy to expect from given fission reactions. When uranium-235 nuclei are bombarded with neutrons, they can split apart in a variety of ways, like glass balls that shatter into pieces of different sizes. In one process, uranium-235 forms barium-142 and krypton-92:

Calculate the energy (in joules) released when 1.0 g of uranium-235 undergoes this fission reaction. The masses of the particles are 

ANTICIPATE Fission processes are used to produce energy; therefore, you should expect that a large amount of energy will be released.

PLAN If you know the mass loss, Δm, you can calculate the energy released by one uranium nucleus by using Einstein’s equation in the form ΔE = Dm * c². To do this, calculate the total mass of the particles on each side of the nuclear equation, take the difference, and substitute the mass difference into this relation. Then determine the number of nuclei in the sample from N = m(sample)/m(atom) and, finally, multiply the energy released from the fission of one nucleus by that number to find the energy released by the sample.

Transcribed Image Text:

235U + n 92 1421 132Ba + Kr + 2 n 56- 92 36-