C1 - Air Quality

OCR 21st Century

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  • Created by: Ellie
  • Created on: 06-01-11 20:59

The Earth's Atmosphere

The atmosphere is made up of several different chemicals, these are:

78% Nitrogen;

21% Oxygen;

1% Argon;

0.04% Carbon Dioxide;

0-4% Water.

Air Pollutants include: Sulphur Dioxide (SO2); Carbon Monoxide (CO); Nitrogen Dioxide (NO2); Carbon Particulates.

The Earth's Atmosphere is roughly 15km thick.

A lot of air pollution comes from burning fossil fuels, these include: gas; coal and oil.

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What are the main air pollutants?

The main air pollutants are: Sulphur dioxide which causes acid rain; Carbon monoxide which causes a poisonous gas which if it reacts with blood, can kill you; Nitrogen dioxide which causes acid rain, asthma and breathing problems; Carbon Particulates which cause lung infections and making things dirty.

Low concentration means that there are very few pollutant molecules around, and high concentration means that there are lots of pollutant molecules around. Concentration levels depend on where you live for example if you live in London it will be higher than somewhere in the countryside.

NO2 levels are higher when traffic is heavier.

Influences of air quality include: vehicles; power stations; homes; factories; mixed pollutants and weather (wind).

Ozone is formed by pollutants reacting together with other gases. The ozone level is higher in the countryside then in cities.

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Measuring an air pollutant

When measuring an air pollutant you should always take more than one measurement. 

You estimate to find the true value.

To find out a mean value (best estimate) you leave out the outlier from the range of measurements.

Real difference means that the ranges do not overlap, however if there is no real difference then that means that the ranges do overlap.

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How are atmospheric pollutants formed?

Any new changes are called chemical change or chemical reactions.

When Nitrogen and Oxygen join with car fuel it creates many new chemicals these include: Carbon Monoxide (CO); Water (H2O); Carbon Dioxide (CO2); Nitrogen monoxide (NO); Nitrogen (N2) and carbon particulates.

In a power station, if they are burning coal it produces CO2 as they carbon atoms and the oxygen atoms join together. In a power station where they burn gas, such as methane, it produces CO2 and H2O as CH4 split and O2 split and join together in a different order to create CO2 and H2O.

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What happens during combustion reactions?

Combustion means chemicals that react rapidly with oxygen to release energy and possibly light.

You need a source of heat, oxygen and fuel to create a fire.


A chemical equation is where you use letters to create the equation, 

A chemical formula is where you use symbols to create the equation,

A word equation is where you use the chemicals names to create the equation.

Reactants are the things before the arrow and products are the result of the chemicals joining.

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Where do all the atoms go?

Atoms are never lost or new ones formed. They are CONSERVED. This means they are joined together to create new atoms.

E.G. 4 hydrogen molecule (H) + 2 oxygen molecules (O) = 2 water molecules (H2O)


Properties of atoms are:

Sulphur - Yellow solid.

Oxygen - Colourless gas, no smell.

Sulphur Dioxide - Colourless gas, choking smell, Extremely harmful.

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What happens to atmospheric pollutants?

Primary pollutants are:


Carbon Monoxide;

Nitrogen Monoxide;

Sulphur Dioxide;



Secondary Pollutants are (products):

Carbon Dioxide;

Nitrogen Dioxide;


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How does air quality affect our health?

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mary 13243

Should mention what particulates are/mean

Hayleigh Stanistreet

quite helpfull :P :) thanks :)


brilliant thanks


amm could improve alittle :)


the water percentage is wrong it's variable so there you go.

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