Question

 What is nuclear fusion? Explain with an example. Write the equation of the reaction involved. 

Answer 1

Nuclear fusion
Nuclear fusion is the process by which two nuclei of light elements combine to form a heavy nucleus.

Example:
When deuterium atoms are heated to an extremely high temperature under extremely high pressure, two deuterium nuclei combine to form a heavy nucleus of helium, and a neutron is emitted. A tremendous amount of energy is liberated in this fusion reaction.  

Reaction: 

`""_1^2H+""_1^2H->""_2^3H+""_0^1n+` 

Tremendous amount of energy