Earth's Evolving Atmosphere

What gas makes up 78% of the Earth's atmosphere today?

• A . Oxygen

• B. Nitrogen

• C. Carbon Dioxide

• D. Argon

Answer explanation

Nitrogen is unreactive and has built up in the atmosphere over time.

What gas makes up 21% of the Earth's Atmosphere?

• A. Oxygen

• B. Nitrogen

• C. Water Vapour

• d. Carbon Dioxide

What percentage of the atmosphere today is made up of carbon dioxide?

• A. 1%

• B. 4%

• C. 0.1%

• D. 0.04%

What is the Earth's early atmosphere believed to be caused by?

• A. Volcanic eruptions

• B. Meteor Strike

• C. Plants

• D. Animals

What reaction puts oxygen into the atmosphere?

• A. Combustion

• B. Respiration

• C. Photosynthesis

• D. Polymerisation

Answer explanation

The earliest organisms to photosynthesise were algae and bacteria.

What gas did ammonia and methane react with that caused them to be removed from our atmosphere?

• A. Carbon Dioxide

• B. Water Vapour

• C. Oxygen

• D. Nitrogen

Answer explanation

The ammonia broke down into nitrogen and water and the methane broke down into carbon dioxide and water.

What type of rock did carbon dioxide get locked up in?

• A. sedimentary

• B. intrusive igneous

• C. Metamorphic

• D. extrusive igneous

What happened to the large proportion of water vapour that was in the early atmosphere?

• A. it is still there

• B. it condensed and fell as rain

• C. it escaped into space

• D. it was taken in by plants

What are the products of photosynthesis?

• A. water + energy

• B. carbon dioxide + water

• C. oxygen + glucose

• D. carbon dioxide + glucose

Which of these gases was not present in the early atmosphere?

• A. Oxygen

• B. Carbon dioxide

• C. Nitrogen

• D. methane