Gases in the atmosphere
Lesson details
Learning outcome
I am able to name the main gases in the atmosphere and describe the test and some uses for each one.
Key learning 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.
- 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.
Keywords
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 misconception
The atmosphere is mostly oxygen.
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.
Teacher tip
The tests for gases could be performed as a demonstration or class practical. An alternative test for carbon dioxide would be to blow through a straw into limewater (make sure a risk assessment is carried out first).
Equipment
See additional material.
Content guidance
Risk assessment required - equipment
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the correct molecular formula for carbon dioxide?
Q2.Match the following key words to their definition.
Q3.Which gas is needed for respiration?
Q4.Which of the following processes requires carbon dioxide?
Q5.Which key word is used to describe a layer of gases that surrounds a planet?
Q6.What is the percentage of oxygen gas in Earth's atmosphere?
Assessment exit quiz
6 Questions
Q1.Which gas makes up about 78% of Earth's atmosphere?
Q2.What is the percentage of oxygen in Earth's atmosphere?
Q3.Which gas in our atmosphere is used to fill some types of food packaging, to keep food fresh for longer?
Q4.Which of the following are uses of carbon dioxide?
Q5.Which gas will form a white precipitate when bubbled through limewater, making the limewater turn milky?
Q6.Order the following statements to describe how to test for the presence of oxygen gas.
To help you plan your 9 science lesson on: Gases in the atmosphere, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 9 science lesson on: Gases in the atmosphere, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 science lessons from the Carbon cycle and climate change unit, dive into the full secondary science curriculum, or learn more about lesson planning.