Year 11 - Science
Stellar evolution
Gravity in space
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit covers the solar system's features, including planets, moons, and satellites. It explains gravity's effect on orbits, the sun's formation from dust and gas, and fusion equilibrium. It also explores red-shift, evidence of an expanding universe, and the link to the Big Bang model.
Lesson Summary
You will learn to describe life cycles of stars and the variations that depend on the mass of a star.
Key Notes
- Radiation pressure from nuclear fusion pushes out from the centre of a star.
- Gravitational force pulls in towards the centre of a star.
- When a star is in balance, forces from radiation pressure are equal in size to gravitational forces.
- A main sequence star is a star in balance for millions of years, until it no can longer fuse hydrogen nuclei.
- After all available hydrogen has been fused, gravity contracts a star raising temperature until other nuclei can fuse.
Vocabulary To Learn
- main sequence star: a star which is fusing hydrogen in its core; these stars are stable for long periods of time
- red giant star: a larger, cooler, star formed after hydrogen in the core has been depleted
- white dwarf star: the white hot core of a star after its outer layers have escaped into space
- supernova: an exploding star, caused by a gravitational collapse after the fuel is exhausted
- neutron star: an incredibly dense star, formed after a supernova
Common Mistakes To Avoid
- Stars just exist and do not change over time.
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
Radiation pressure from nuclear fusion pushes out from the centre of a star. Gravitational force pulls in towards the centre of a star.
2. Define this scientific word and use it in context. 'main sequence star'
a star which is fusing hydrogen in its core; these stars are stable for long periods of time. Include the word in a full scientific explanation, not as a single label.
3. Correct this common scientific misunderstanding.
Mistake: Stars just exist and do not change over time. Correction: Explain the cause and effect of changes in stars and support pupils in explaining these ideas in their own words.
More Lessons In This Unit
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