GENERAL KNOWLEDGE

Detailed explanation-1: -(The number of protons in the nucleus is what makes the atoms “uranium.") The U238 atoms contain 146 neutrons, the U235 atoms contain 143 neutrons, and the U234 atoms contain only 142 neutrons. The total number of protons plus neutrons gives the atomic mass of each isotope-that is 238, 235, or 234, respectively.

Detailed explanation-2: -The nucleus of the U-235 atom contains 92 protons and 143 neutrons, giving an atomic mass of 235 units. The U-238 nucleus also has 92 protons but has 146 neutrons – three more than U-235 – and therefore has a mass of 238 units.

Detailed explanation-3: -Uranium-235 is one fissile isotope, thus it can sustain nuclear fission chain reaction with thermal neutron. Uranium-238 is not a fissile isotope and thus cannot sustain chain reaction with any neutron.

Detailed explanation-4: -The most abundant uranium isotope is uranium-238; nuclear reactors use uranium-235 to generate heat. (The difference between these two isotopes is the number of neutrons in their nuclei; both have 92 protons.)

Detailed explanation-5: -The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons).