New
New
Year 9

Gases in the atmosphere

I am able to name the main gases in the atmosphere and describe the test and some uses for each one.

New
New
Year 9

Gases in the atmosphere

I am able to name the main gases in the atmosphere and describe the test and some uses for each one.

Lesson details

Key learning points

  1. About 79% of the atmosphere is nitrogen gas that is very unreactive.
  2. Nitrogen gas is often used to fill food packaging to provide an unreactive atmosphere.
  3. About 20% of the atmosphere is oxygen.
  4. The test for oxygen gas is that it relights a glowing splint.
  5. The test for carbon dioxide gas is that it forms a white precipitate that turns limewater milky.

Common misconception

The atmosphere is mostly oxygen.

Explain that the atmosphere is ~79% nitrogen and ~20% oxygen.

Keywords

  • Atmosphere - The atmosphere is a layer of gas that surrounds a planet. It may contain small amounts of solid and liquid particles.

  • Mixture - A mixture is a material that contains two or more different substances, which can be physically separated.

  • Respiration - Respiration is a chemical process that uses oxygen from the air, and glucose to provide energy for life processes.

  • Precipitate - A precipitate is an insoluble solid formed when two solutions react together.

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).
Teacher tip

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
What is the correct molecular formula for carbon dioxide?
CO
CO2
C₂O
Correct answer: CO₂
Q2.
Match the key term with the correct definition.
Correct Answer:mixture,contains different substances, which can be physically separated

contains different substances, which can be physically separated

Correct Answer:element,made from only one type of atom

made from only one type of atom

Correct Answer:compound,contains different elements chemically joined together

contains different elements chemically joined together

Q3.
Which gas is needed for respiration?
Correct Answer: oxygen, oxygen gas, O2
Q4.
Which of the following processes requires carbon dioxide?
combustion
respiration
Correct answer: photosynthesis
neutralisation
Q5.
Which key word is used to describe a layer of gas that surrounds a planet?
space
Correct answer: atmosphere
rocks
vacuum
Q6.
What is the percentage of oxygen gas in Earth's atmosphere?
79%
Correct answer: 21%
1%
0.04%

6 Questions

Q1.
Which gas makes up ~79% of Earth's atmosphere?
Correct answer: nitrogen
oxygen
argon
carbon dioxide
methane
Q2.
What is the percentage of oxygen in Earth's atmosphere?
0.04%
1%
Correct answer: 21%
79%
100%
Q3.
Which gas in our atmosphere is used to provide an unreactive atmosphere in food packaging?
Correct Answer: nitrogen gas, nitrogen, N2
Q4.
Which of the following are uses of carbon dioxide?
Correct answer: for photosynthesis by plants
Correct answer: in fire extinguishers
for plants and animals to respire
to provide an unreactive atmosphere in food packaging
Correct answer: in carbonated drinks
Q5.
Which gas will form a white precipitate when bubbled through limewater, making the limewater turn milky?
nitrogen
oxygen
argon
Correct answer: carbon dioxide
Q6.
Order the following statements to describe how to test for the presence of oxygen gas.
1 - light a splint
2 - extinguish the splint to leave a glowing splint
3 - place the glowing splint in oxygen gas
4 - the glowing splint will relight

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