Question

The fusion reaction starts in a star when the temperature of the gas in its core is ______ or more.

• A. one million degrees celsius
• B. 5 million degrees celsius
• C. 8 million degrees celsius
• D. 10 million degrees celsius

Answer 1

The correct option is D

10 million degrees celsius

1. A star is nothing but a large glowing ball of gas.
2. Its main component is hydrogen gas.
3. Since the star core is under tremendous pressure, as a result, the atoms of hydrogen are squeezed into a tiny space.
4. Therefore the temperature of the star core rise and when it reaches 10 million degrees celsius hydrogen atoms fuse together to form helium atoms.
5. This is known as a fusion reaction and it releases a vast amount of energy and the star starts glowing.

Hence, option D is correct.