GCSE Chemistry- Atmosphere

Atmosphere, Combustion, Pollution, Global Warming

Carbon Footprint

The total amount of carbon dioxide (and other greenhouse gases) emitted over the full life cycle of a produce, service or event.

Oxygen percentage (early atmosphere)

0

Oxygen percentage (current atmosphere)

21

Nitrogen percentage (early atmosphere)

0

Nitrogen percentage (current atmosphere)

78

CO2 percentage (early atmosphere)

70

CO2 percentage (current atmosphere)

0.04

Water vapour percentage (early atmosphere)

10

Water vapour percentage (current atmosphere)

0.06

Methane percentage (early atmosphere)

20

Methane percentage (current atmosphere)

0

Why is there less water vapour in today’s atmosphere?

Water vapour has condensed from gas to liquid in the ocean with decreasing temperatures.

Why is there more oxygen in today’s atmosphere?

Increased vegetation has increased oxygen levels.

Why is there less CO2 in today’s atmosphere?

CO2 has been absorbed into the ocean, locked up in the formation of sedimentary rocks and absorbed by vegetation.

How was the ozone layer created?

Oxygen created the ozone layer which blocks harmful rays from the sun.

How was nitrogen formed?

Ammonia reacted with oxygen to form nitrogen. Bacteria converted nitrates from the soil into nitrogen in the air.

How was oxygen introduced to the atmosphere?

As algae developed and photosynthesised, plants took in carbon dioxide and released oxygen.

Complete Combustion

When fuels burn in the presence of oxygen, carbon dioxide and water are given off.

Incomplete Combustion

This occurs when there is not enough oxygen for a fuel to react with. Carbon monoxide and water are given off.

Carbon Monoxide

Combines with haemoglobin in red blood cells, preventing oxygen from combining. This reduces the amount of oxygen in the bloodstream

Mild Carbon Monoxide Intake

Dizziness

Severe Carbon Monoxide Intake

Death

Fuel

A fuel is any substance that is burned to release energy.

How can you test for the presence of CO2?

Bubble CO2 through limewater. If it is present, the limewater turns milky white/cloudy.

Carbon Particulates

Tiny, solid particles that are made up of carbon (also released when fuels undergo incomplete combustion)

What can carbon particulates do?

Make buildings look dirty, reduce air quality, cause respiratory conditions, contribute towards global dimming.

Sulfur Dioxide (SO2)

When a fuel containing traces of sulfur is burnt, sulfur is oxidised into sulfur dioxide.

Why is sulfur dioxide produced in a petrol engine?

There are traces of sulfur in the petrol.

How is acid rain formed?

Sulfur dioxide goes up into the clouds and forms dilute sulfuric acid, which falls as acid rain.

What can acid rain do?

Damage buildings and plants, and harm aquatic life.

How can we reduce sulfur dioxide pollution?

By using low sulfur fuels and burning less fossil fuels.

Nitrogen Oxide (NO + NO2)

Nitrogen and oxygen in the air combine in the presence of heat. Usually formed in hot car engines.

Global Warming

The increase in the Earth’s temperature due to greenhouse gases.

How do greenhouse gases increase Earth’s temperature?

By acting like an insulating layer in the atmosphere and trapping heat.

What are the four most common greenhouse gases?

Carbon Dioxide, Methane, Water Vapour, Nitrogen Dioxide

Effects of global warming

Polar ice caps melting, changes in rainfall patterns, increased severity of storms, different distribution of wild species.

Carbon Neutral

The CO2 that plants take in when they grow is released when the wood from trees is burned. These cancel each other out so there is no net CO2 emissions.

Why is historical data on global temperature less accurate?

Less data was taken over fewer locations and methods to collect data were less accurate

How does human and animal activity increase greenhouse emissions?

Farm animals, deforestation, landfill sites, burning fossil fuels.

How does radiation enter the atmosphere?

UV (short wavelength) passes through the atmosphere. The Earth’s surface absorbs and re-emits it as IR (long wavelength) radiation. This is absorbed by greenhouse gases which re-radiate in all directions.

Give one measure an individual could take to reduce their carbon emissions.

Walking/cycling instead of driving

Give one way that governments can act to reduce CO2 emissions

By placing fines for cutting down trees so they can still absorb CO2 from the atmosphere