EVERYDAY SCIENCE

Detailed explanation-1: -The nucleus of the U-235 atom comprises 92 protons and 143 neutrons (92 + 143 = 235). When the nucleus of a U-235 atom captures a moving neutron it splits in two (fissions) and releases some energy in the form of heat, also two or three additional neutrons are thrown off.

Detailed explanation-2: -When a U-235 nucleus absorbs an extra neutron, it quickly breaks into two parts. This process is known as fission (see diagram below). Each time a U-235 nucleus splits, it releases two or three neutrons. Hence, the possibility exists for creating a chain reaction.

Detailed explanation-3: -Uranium is the fuel most widely used by nuclear plants for nuclear fission. Uranium is considered a nonrenewable energy source, even though it is a common metal found in rocks worldwide. Nuclear power plants use a certain kind of uranium, referred to as U-235, for fuel because its atoms are easily split apart.

Detailed explanation-4: -With a complete combustion or fission, approx. 8 kWh of heat can be generated from 1 kg of coal, approx. 12 kWh from 1 kg of mineral oil and around 24, 000, 000 kWh from 1 kg of uranium-235. Related to one kilogram, uranium-235 contains two to three million times the energy.

Detailed explanation-5: -For uranium-235 (total mean fission energy 202.79 MeV), typically  169 MeV appears as the kinetic energy of the daughter nuclei, which fly apart at about 3% of the speed of light, due to Coulomb repulsion. Also, an average of 2.5 neutrons are emitted, with a mean kinetic energy per neutron of  2 MeV (total of 4.8 MeV).