The source of the sun's heat is nuclear A. fission. B. fusion. C. separation. D. disintegration

The source of the sun's heat is nuclear fusion.

Answer: B

Explanation

Nuclear fusion is defined as the reaction where two or more nuclei combine together to form two or more product nuclei.

In nuclear fusion reaction, the difference in the mass of the reactant nuclei converts into the energy released or absorbed along with the product nuclei.

Generally lighter elements like hydrogen and helium are more prone to undergo nuclear fusion and produce higher weight nuclei along with release of high amount of energy.

The lighter reacting elements can easily overcome the attractive forces between them and combine to form the product nuclei with release of energy.

In sun, the hydrogen and helium fusion chain reaction provides the necessary energy to emit heat radiations and remain as an active star.

Answer: The source of the sun's heat is B; Nuclear Fusion.

Explanation:

The energy is produced when the hydrogen atoms are put together (fused) and this is when helium is formed. When the helium is formed the matter converts to energy. This is what powers the sun. Research into nuclear fusion has been ongoing since the 1940's.