C14 Earth's Atmosphere

What was the Earth's early atmosphere mainly composed of?

• Carbon dioxide and water vapour

• Oxygen and nitrogen

• Hydrogen and helium

• Methane and ammonia

What process caused the amount of carbon dioxide to decrease and oxygen to increase?

• Condensation

• Evaporation

• Volcanic activity

• Photosynthesis

Approximately how old is the Earth?

• 4.6 billion years

• 3.5 billion years

• 5.2 billion years

• 2.8 billion years

What theory suggests the source of the early atmosphere?

• Biological activity

• Meteorite impacts

• Volcanic activity

• Solar winds

What gases were likely released by volcanic activity in the early atmosphere?

• Hydrogen and helium

• Carbon dioxide, ammonia, and methane

• Oxygen and nitrogen

• Ozone and argon

What happened to the water vapour released by volcanic activity?

• It formed clouds

• It escaped into space

• It remained as vapour

• It formed the oceans

Why has nitrogen gradually built up in the atmosphere?

• Because it was brought by comets

• Because it was released by plants

• Because it is unreactive

• Because it is reactive

What is the most abundant gas in the modern atmosphere?

• Nitrogen

• Carbon dioxide

• Oxygen

• Argon

For how long have the proportions of different gases in the atmosphere been relatively stable?

• 200 million years

• 500 million years

• 100 million years

• 1 billion years

What is the significance of photosynthesis in the change of the Earth's atmosphere?

• It increased the amount of water vapour

• It decreased the amount of oxygen

• It increased the amount of oxygen and decreased carbon dioxide

• It had no significant effect