Chemistry of the Atmosphere

• Chemistry
• Upper Secondary (Key Stage 4)
• GCSE

Chemistry of the Atmosphere

For 200 million years, the proportions of different gases in the atmosphere have been much the same as they are today.

1.  80% is Nitrogen
2.  20% Oxygen
3. small proportions of various other gases, including carbon dioxide, water vapour and noble gases.

Our current atmosphere.

What is the most abundant gas in the Earth's atmosphere?

1. Nitrogen
2. Argon
3. Oxygen
4. Carbon dioxide

Which gas is responsible for the greenhouse effect?

1. Methane
2. Oxygen
3. Nitrogen
4. Carbon dioxide

What is the approximate percentage of oxygen in the atmosphere?

1. 1%
2. 50%
3. 78%
4. 21%

What is the role of argon in the atmosphere?

1. It is essential for respiration
2. It contributes to the greenhouse effect
3. It supports combustion
4. It is a non-reactive gas

Describe the composition of our atmosphere.

Evidence is limited because of the time scale of 4.6 billion years and theories have changed/developed over time.

One theory suggests that during the first billion years of the Earth’s existence…

o There was intense volcanic activity that released gases that formed the

early atmosphere

At the start of this period, the atmosphere may have been like the

atmospheres of Mars and Venus today: mainly CO₂ with little or

no O₂  (g)

Volcanoes also produced nitrogen (N₂) which gradually built up in

the atmosphere & there may have been small proportions of

methane (CH₄) and ammonia (NH₃) 

▪ CO₂ dissolved in the water and carbonates were precipitated

producing sediments, reducing the amount of CO₂ in the atmosphere. 

Water vapour condensed to form the oceans

Algae & plants produced the O₂ that is now in the atmosphere by photosynthesis.

 Algae first produced oxygen about 2.7 billion years ago and soon after this oxygen appeared in the atmosphere.

 Over the next billion years plants evolved and the % oxygen gradually increased to a level that enabled animals to evolve.

Algae and plants decreased the % CO₂ in the atmosphere by photosynthesis 

CO₂ was also decreased by the formation of sedimentary rocks that contain carbon.

The production of fossil fuels from the remains of dead plants and animals reduced the amount of CO₂ in the atmosphere.

Why is evidence limited for the composition of Earth's early atmosphere.

What effect did volcanoes have on the earth Earth's atmosphere?

Early Earth's atmosphere was similar to

1. Earth and Mars
2. Mars and Venus
3. Saturn and Mars
4. Mars and Mercury

Which gas did volcanoes release which makes up a lot of our atmosphere now?

1. Oxygen
2. Carbon Dioxide
3. Methane
4. Nitrogen

Which living things created oxygen in the atmosphere?

1. Animals
2. Shellfish and molluscs
3. Plants and algae
4. Plants and animals

Name the process by which algae and plants which releases oxygen into the atmosphere?

1. respiration
2. Aerobic respiration
3. Anaerobic respiration
4. Photosynthesis

Which type of rock decreases the amount of Carbon Dioxide in the atmosphere?

1. metapmorphic
2. igneous
3. sedimentary
4. sedentary

Fossil fuels are made from

1. Plants
2. Bones
3. Flesh of dinosaurs
4. Plants and animals

Discuss how carbon dioxide is reduced from the atmosphere (there are 3 ways)

Describe which living creatures released oxygen into the atmosphere

Describe how the oceans were formed.

What are the three main types of fossil fuels?

1. Solar, wind, hydroelectric
2. Coal, oil, natural gas
3. Coal, uranium, shale gas
4. Geothermal, biomass, nuclear

Which fossil fuel is the most abundant globally?

1. Coal
2. Uranium
3. Oil
4. Natural gas

What is the primary use of fossil fuels?

1. Textile production
2. Food production
3. Energy production
4. Medicine manufacturing

What process do algae use to form oxygen in the atmosphere?

1. Combustion
2. Fermentation
3. Photosynthesis
4. Respiration

What is the primary source of oxygen production in the Earth's atmosphere?

1. Bacteria
2. Fungi
3. Algae
4. Moss

Which environmental factor is crucial for algae to produce oxygen?

1. Sunlight
2. Extreme Cold
3. Acid Rain
4. Pollution