Nuclei Test - 7

U - 236 has larger delayed neutron fraction.

Because graphite is thermally stable and conducts heat well.

Binding energy is the energy required to separate the nucleons from nucleus at infinite separation. Binding energy determines the stability of nucleus. Nucleus of intermediate mass are most stable as they have greatest binding energy per nucleon of 8.5 MeV
Light and heavy nuclei are unstable as they take part in nuclear fission and fusion reactions.

As nuclear fusion occurs with high temperature, high pressure and high particle density.

In nuclear reactions momentum, the sum of mass and energy and charges are conserved.
During a nuclear reaction, the mass of reactants may be more than products. The lost mass is converted into an enormous amount of energy. According to the conservation of mass and energy law, the total quantity of matter and energy remains constant in an isolated system.
Charges are conserved as total charge before and after the nuclear reaction remains same.

​​​​​6 α particle → Atomic No. decrease by 12,
mass no by 24
4 β particle → Atomic No. increase by 4,
mass no remain same

10% substance decays in 10 days
substance left after 10 days = 90%
After 20 days, substance left
= 0.9 × 0.9
= 0.81
= 81%
After 24 days, substance left
=0.96 × 0.81
= .777
= 78%