# Air Quality

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.