New
New
Year 11
OCR
Higher

Evolution of Earth's atmosphere

I can describe how Earth’s atmosphere developed over billions of years.

New
New
Year 11
OCR
Higher

Evolution of Earth's atmosphere

I can describe how Earth’s atmosphere developed over billions of years.

Lesson details

Key learning points

  1. Early volcanic activity is thought to have made an atmosphere of carbon dioxide and nitrogen billions of years ago.
  2. Carbon dioxide can dissolve in oceans and form carbonates which, over millions of years, can form sedimentary rock.
  3. The amount of carbon dioxide was reduced by the formation of sedimentary rocks and photosynthesis by algae and plants.
  4. Algae and plants produced the oxygen that is now in the atmosphere by photosynthesis.
  5. Phytoplankton in the oceans are responsible for roughly half of all oxygen production that takes place today.

Common misconception

The Earth's atmosphere has always contained oxygen. The atmosphere's composition is static and unchanging.

Clarify the development of oxygen through photosynthesis. Describe how atmospheric composition has evolved over time due to geological and biological processes.

Keywords

  • Volcano - A volcano is an opening on the surface of a planet or moon through which molten rock, rock fragments and gases erupt.

  • Sedimentary rock - Sedimentary rocks are a type of rock formed from the compression of sediments (rock fragments, minerals and remains of dead plants and animals).

  • Photosynthesis - The process of photosynthesis is where energy from sunlight is used to convert carbon dioxide and water into glucose and oxygen.

  • Algae - Algae are a diverse range of unicellular or multicellular photosynthetic organisms. Many algae are aquatic.

  • Phytoplankton - Some types of algae belong to a group of microscopic marine photosynthetic organisms called phytoplankton.

Be aware that there are different theories about early Earth. The volcanic activity theory in the lesson is based on analysing air from ancient rock samples.
Teacher tip

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.
Earth's atmosphere comprises approximately 21% of which gas?
Correct Answer: oxygen
Q2.
What is the percentage of carbon dioxide in Earth's atmosphere?
78%
21%
1%
Correct answer: 0.04%
Q3.
How old is Earth thought to be?
4 million years
Correct answer: 4.5 billion years
2 million years
200 billion years
Q4.
The atmosphere on Earth has been in roughly the same proportions for how many million years?
Correct Answer: 200
Q5.
What name is given to the layer of gas that surrounds a planet?
Correct Answer: atmosphere
Q6.
What is the name of this process?
An image in a quiz
respiration
combustion
Correct answer: photosynthesis
sedimentation

6 Questions

Q1.
Which of the following released gases forming Earth's early atmosphere?
plants photosynthesising
animals respiring
Correct answer: volcanic activity
combustion of fuels
Q2.
What is the name of the process which uses energy from sunlight to convert carbon dioxide and water into glucose and oxygen?
Correct Answer: photosynthesis, photosynthesising
Q3.
Which was the most abundant gas in the early atmosphere?
nitrogen
oxygen
argon
Correct answer: carbon dioxide
Q4.
Algae evolving led to increased levels of which gas in the atmosphere?
Correct Answer: oxygen
Q5.
Put the statements into the correct order to describe how the oceans formed.
1 - Volcanic activity released water vapour into the atmosphere.
2 - The surface temperature of Earth cooled.
3 - As the surface temperature reached 100℃ water vapour condensed.
4 - Liquid water fell to Earth forming the oceans.
Q6.
Which of the following led to decreased levels of carbon dioxide in the atmosphere?
respiration by animals
Correct answer: carbon dioxide dissolving in the oceans
Correct answer: algae and plants photosynthesising
Correct answer: carbon being 'locked up' in sedimentary rocks and fossil fuels
combustion of fuels