What is self-sustained nuclear reaction?

What do you mean by nuclear reaction? What quantities are conserved in nuclear reaction? What is Q-value of nuclear reaction?

What is meant by nuclear chain reaction? Explain, why uranium "_92U^238 is not suitable for chain reaction.

What is effective nuclear charge ?

What is exoenergic nuclear reaction?

What is controlled nuclear chain reaction? describe a nuclear reactor and function of each component.

What is the principle of nuclear reactor?