Question

the quantities, which remain conserved in a nuclear reaction

Answer 1

This is an interesting question. In analyzing nuclear reactions, we apply the many conservation laws. T
he quantities which remain conserved in a nuclear reaction are as follows:

Charge 
Mass
Momentum
Angular momentum


Electric charge, lepton number, and baryon number are also conserved.  No. of protons and neutrons are separately conserved.  Conservation of momentum and energy produce an elastic and inelastic collision.

 Hope this will help you.

Answer 2

Nuclear Reactions is the process in which 2 nuclear particles interact to produce 2 or more nuclear particles or Gamma Rays.
In nuclear Reactions, following laws are obeyed:
1.Law of conservation of charge
2. Law of conservation of momentum
3. Law of conservation of Energies
4.Law of conservation of angular momentum. 
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So the quanties which remain conserved in nuclear Reactions are:
Charge
Momentum
Energy
Angular momentum