Starter quiz
- What is the correct molecular formula for carbon dioxide?
- CO
- CO2
- C₂O
- CO₂ ✓
-
- Match the key term with the correct definition.
- mixture⇔contains different substances, which can be physically separated ✓
- element⇔made from only one type of atom ✓
- compound⇔contains different elements chemically joined together ✓
- Which gas is needed for respiration?
- 'oxygen' ✓
- Which of the following processes requires carbon dioxide?
- combustion
- respiration
- photosynthesis ✓
- neutralisation
-
- Which key word is used to describe a layer of gas that surrounds a planet?
- space
- atmosphere ✓
- rocks
- vacuum
-
- What is the percentage of oxygen gas in Earth's atmosphere?
- 79%
- 21% ✓
- 1%
- 0.04%
-
Exit quiz
- Which gas makes up ~79% of Earth's atmosphere?
- nitrogen ✓
- oxygen
- argon
- carbon dioxide
- methane
-
- What is the percentage of oxygen in Earth's atmosphere?
- 0.04%
- 1%
- 21% ✓
- 79%
- 100%
-
- Which gas in our atmosphere is used to provide an unreactive atmosphere in food packaging?
- 'nitrogen gas' ✓
- Which of the following are uses of carbon dioxide?
- for photosynthesis by plants ✓
- in fire extinguishers ✓
- for plants and animals to respire
- to provide an unreactive atmosphere in food packaging
- in carbonated drinks ✓
-
- Which gas will form a white precipitate when bubbled through limewater, making the limewater turn milky?
- nitrogen
- oxygen
- argon
- carbon dioxide ✓
-
- 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
Worksheet
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Lesson Details
Key learning points
- About 79% of the atmosphere is nitrogen gas that is very unreactive.
- Nitrogen gas is often used to fill food packaging to provide an unreactive atmosphere.
- About 20% of the atmosphere is oxygen.
- 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.
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.
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