Air Quality

Subject classification: this is a biology resource.

This resource is geared to the OCR 2011 Core Science GCSE module C1.

Evolution of the Atmosphere

The atmosphere has not always been like it is today - it had to get to that state.

Phase 1 - Volcanic Gas

• The volcanoes on Ancient Earth erupted often and they gave out carbon dioxide, water vapour and nitrogen - this made the atmosphere form.
• Oceans appeared when water vapour condensed.

Phase 2 - Plants make oxygen

• Green plants grew in the carbon dioxide-filled environment.
• These produced oxygen through respiration.
• This allowed complex organisms like humans to evolve.

Today's Atmosphere

You breath it in all the time, but do you know what is in it?

The constituents of the atmosphere

• There are three main gases: 78% nitrogen, 21% oxygen and 1% argon.
• There are small amounts of other gases within.

Humans are altering the air's contents

• Some of these small gases pollute the air, like carbon dioxide, carbon monoxide, particulates, sulphur dioxide, and nitrogen oxide.
• They are released by burning fossil fuels and volcanoes erupting.
• They can cause environmental damage.

Chemical reactions

Chemical reactions occur when atoms rearrange themselves.

Reactants and products are often different

Reactants and products can often do very different things, as chemical reactions cause atoms to change places. Note that no atoms are ever lost.

Fossil Fuels

Modern life is reliant on fossil fuels.

Hydrocarbons

Fossil fuels are hydrocarbons, which means they are made of hydrogen and carbon. They are made by the compression of ancient organisms.

Oxidation

Oxidation is part of the fossil fuel process. When coal is burnt the carbon reacts with the oxygen in the air. This adds carbon dioxide to the atmosphere.

Air Pollution by carbon

Carbon Dioxide

• It has one carbon atom and two oxygen atoms.
• Plants remove it from the atmosphere.
• It causes global warming.

Carbon Monoxide

• It has one carbon atom and one oxygen atom.
• It is poisonous to humans.

Carbon particulates

• These tiny particles of carbon can make buildings look dirty when they fall as soot.

Air Pollution by Sulphur

Sulphur is also spelt as sulfur. It's your choice.

Production

• The main pollutant from sulphur is sulphur dioxide.
• It is produced by burning impurities in coal.

Dangers

• The main dangers is acid rain.
• It poisons lakes and cause statues to be eroded.

Air Pollution by Nitrogen

Nitrogen is the most common gas in our atmosphere - what harm could it do?

Nitrogen Monoxide

• It is formed when nitrogen and oxygen are exposed together to a high temperature, like in a car exhaust.
• It makes acid rain.

Nitrogen Dioxide

• It is formed when nitrogen and oxygen are exposed together to a high temperature, like in a car exhaust.
• It makes acid rain.
• Yes, it is pretty much the same.

Reducing Pollution

What can we do to stop pollution?

Power stations

We can use less electricity, or use alternative sources.

Cars

We can use catalytic converters which convert dangerous gases into less dangerous ones. We can also use alternative fuels.

Plant trees

Trees absorb carbon dioxide and provides oxygen.