Nuclear Physics

The number of fissions per second is given by:
Given that 1 MeV = J, the energy per fission is:
Power output is 1000 kW = W. Thus,

Balancing the mass number and atomic number,
Solving,
which corresponds to a neutron.

Isobars are nuclei with the same mass number but different atomic numbers. Here,
Since they have different atomic numbers but nearly the same mass number, they are isobars.

Packing fraction is given by:
where is the actual mass of the nucleus, and is its atomic mass.

In nuclear fission, slow-moving (thermal) neutrons are more likely to be captured by heavy nuclei such as , initiating a chain reaction. Fast neutrons need to be moderated to thermal energies to sustain fission reactions efficiently.

Radioactive decay follows the exponential law:
Rewriting it, we get: