Year 9 - Science
Gases in the atmosphere
Carbon cycle and climate change
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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 explores the rock cycle and the formation of igneous, sedimentary, and metamorphic rocks. It also examines the atmosphere's composition, human-induced carbon dioxide production, and its impact on climate. Focus is on interpreting data, identifying patterns, and presenting explanations.
Lesson Summary
You am able to name the main gases in the atmosphere and describe the test and some uses for each one.
Key Notes
- Earth's atmosphere is mostly within 7 to 15 km of its surface.
- Earth's atmosphere is 78% N₂ and 21% O₂, with very small amounts of other gases and particles of liquids and solids.
- Greenhouse gases keep Earth's temperature warm enought for human life.
- The test for oxygen gas is that it relights a glowing splint.
- The test for carbon dioxide gas is that it forms a white precipitate that turns limewater milky.
Vocabulary To Learn
- atmosphere: a layer of gases that surrounds a planet and may contain small amounts of solid and liquid particles
- mixture: a combination of two or more substances that are physically mixed and can be separated
- respiration: a chemical process that uses oxygen from the air and glucose to provide energy for life processes
- precipitate: an insoluble solid formed when two solutions react together
Common Mistakes To Avoid
- The atmosphere is mostly oxygen.
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
Earth's atmosphere is mostly within 7 to 15 km of its surface. Earth's atmosphere is 78% N₂ and 21% O₂, with very small amounts of other gases and particles of liquids and solids.
2. Define this scientific word and use it in context. 'atmosphere'
a layer of gases that surrounds a planet and may contain small amounts of solid and liquid particles. Include the word in a full scientific explanation, not as a single label.
3. Correct this common scientific misunderstanding.
Mistake: The atmosphere is mostly oxygen. Correction: Describe the atmosphere as ~78% unreactive nitrogen and ~20% oxygen. Explain that if the atmosphere were mostly oxygen, the planet would quickly be engulfed in fire.
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