# A star begins its life as a cloud of gas and dust called a nebula. Describe the sequence of stages a star similar in mass to the Sun goes through from the moment nuclear fusion begins until it reaches its final stable state.

> Eduqas A-Level Physics — 6.3 Stellar evolution and cosmology (A-Level only) · Describe · 5 marks

## Mark scheme (5 marks)

1. Nuclear fusion of hydrogen begins in the core, and the star enters the main sequence stage
2. When hydrogen in the core is exhausted, the star expands to become a red giant
3. The red giant sheds its outer layers, forming a planetary nebula
4. The hot core that remains is a white dwarf
5. The white dwarf gradually cools over time to become a black dwarf (final stable / cool state)

## Key terms

- [nuclear fusion](https://www.gradenine.co.uk/glossary/nuclear-fusion)

## Related

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-star-begins-its-life-as-2d727c54) · Published by Druglandscape Ltd.