The composition & evolution of the atmosphere

The Earth’s early atmosphere may have been mainly carbon dioxide, nitrogen and water vapour.

The pie chart shows the relative amounts of each gas in the Earth’s early atmosphere.

Calculate the percentage of nitrogen in the Earth’s early atmosphere.

Some of the gases in the Earth’s atmosphere today are called greenhouse gases.

What effect do greenhouse gases have in the Earth’s atmosphere?

Tick (✓) one box.

Which of these gases is a greenhouse gas?

Tick (✓) one box.

The Earth’s early atmosphere may have been mainly carbon dioxide.

Which statement about the carbon dioxide is incorrect ?

A It dissolved in the oceans.

B It reacted with nitrogen.

C It was absorbed by plants during photosynthesis.

D It was released by volcanoes.

Scientists think the Earth’s oxygen-rich atmosphere developed due to photosynthesis by plants.

Which gas in the Earth’s early atmosphere did plants absorb during photosynthesis?

A Ammonia

B Carbon dioxide

C Methane

D Sulfur dioxide

It is thought that the gases in Earth’s early atmosphere were released by volcanoes.

The table shows the amounts of different gases released by a volcano.

Which of the gases are carbon dioxide and water vapour?

A W and Z

B W and Y

C X and Y

D X and Z

Where do scientists think that the oxygen in the Earth’s atmosphere came from?

A Earthquakes

B Green plants

C Thunderstorms

D Volcanic activity

The Earth’s atmosphere contains 78% nitrogen and 21% oxygen. The remaining 1% is listed in the table.

What is the percentage of carbon dioxide in the Earth’s atmosphere?

A 0.01%

B 0.04%

C 0.06%

D 0.08%

The Earth’s early atmosphere was mainly water vapour and carbon dioxide.

The Earth’s atmosphere today is mainly nitrogen and oxygen with small amounts of other gases including carbon dioxide.

Complete the bar chart to show the percentage of nitrogen and oxygen found in the Earth’s

atmosphere today.

Explain how the amounts of water vapour and carbon dioxide in the Earth’s early atmosphere decreased over time.

Water vapour........

Carbon dioxide........

Explain how the amount of oxygen in the Earth’s atmosphere has increased over time.

The Earth’s early atmosphere may have trapped more of the sun’s heat than Earth’s atmosphere traps today.

Give a reason why.

The amount of carbon dioxide in the Earth’s atmosphere is 409.8 parts per million.

1 part per million is equal to 0.0001%

Calculate the percentage of carbon dioxide in the Earth’s atmosphere today.

Give your answer to 3 decimal places.

What produced the gases present in the Earth’s early atmosphere?

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What is the percentage of oxygen in the Earth’s atmosphere today ?

The amounts of carbon dioxide and water vapour in the Earth’s early atmosphere decreased over time.

Draw lines to connect each gas with the correct description of how it decreased over time

The Earth’s atmosphere today contains gases from Group 0 in the Periodic Table.

The table shows the amounts of the gases from Group 0 in the Earth’s atmosphere

The total amount of the gases from Group 0 is 0.938%.

Complete the table by calculating the exact amount of krypton in the Earth’s atmosphere today.

Write your answer in the box in the table.

What is a property of the Group 0 gases?

Tick (✓) one box.

The graph shows how the amounts of carbon dioxide, nitrogen and oxygen in the Earth’s early atmosphere may have changed over time.

How many years ago does the graph suggest that photosynthesis started to happen?

A 1.2–1.6 billion years ago

B 2.2–2.6 billion years ago

C 3.2–3.6 billion years ago

D 4.0–4.4 billion years ago

The Earth’s early atmosphere contained little or no oxygen.

Which process produced the oxygen found in the Earth’s atmosphere today?

A Burning fossil fuels

B Photosynthesis by plants and algae

C Respiration by bacteria

D Volcanic activity

The composition of the Earth’s atmosphere has changed over the last 4.5 billion years.

Which gas has increased by the largest amount?

A Ammonia

B Nitrogen

C Oxygen

D Water vapour

The Earth’s early atmosphere is thought to have contained large amounts of carbon dioxide.

Which process does not explain how the amount of carbon dioxide in the atmosphere was decreased?

A It became ‘locked up’ in fossil fuels.

B It dissolved in the oceans.

C It reacted to produce metal oxides found in metal ores.

D It was used in photosynthesis by green plants.

Which graph shows the correct percentages of the three main gases in the atmosphere today?

Look at the table.

Which row in the table shows the correct percentages of gases in the present day atmosphere?

Complete the sentences about how the Earth’s atmosphere has evolved.

Choose words from the list.

argon condensed

melted nitrogen

oxygen sunlight

thunderstorms volcanoes

The earliest atmosphere was made up of ammonia, carbon dioxide and water vapour.

These gases were released by........

The water vapour........ to form the oceans.

Ammonia was converted by bacteria in the soil to make........

The earliest plants photosynthesised.

They absorbed carbon dioxide and released........ gas.

Look at the table.

Which row in the table shows the percentages of gases in the present day atmosphere?