78% nitrogen 21% oxygen 0.04% carbon dioxide 0.96% other gases

CO

SO₂

NOx

CO₂

Formed by incomplete combustion (burning with too little O₂). This when inhaled prevents the blood from carrying enough oxygen leading to suffocation

Formed by burning fossil fuels containing sulphur impurities. Dissolves in water in clouds causing acid rain (H₂SO₄). This corrodes buildings, damages ecosystems and irritates the respiratory system when inhaled

Formed by burning fuels in engines and power stations. Dissolves in water in clouds causing acid rain (HNO₃). Irritates the respiratory system when inhaled.

Currently 0.04% of air but increasing due to burning fossil fuels and deforestation. CO₂ absorbs infrared radiation from the ground once it has been heated by the sun. This causes global warming via the greenhouse effect.

Caused by too much CO₂ this is a problem because temperatures are rising faster than nature's ability to adapt. This makes the future of farming and sustaining ecosystems very difficult.

Used for cooking, cleaning and transporting waste at home. Used for cooling hot machinery, cleaning and as a solvent in industry.

Our main source of water drinking water comes from rivers and lakes, but this has harmful bacteria, fertilisers and industrial waster meaning it is unsafe to drink. Sea water is too big a percentage of dissolved water to drink safely and too expensive to extract these salts in mass.

Chlorination - chlorine is added to the water which destroys the bacteria

Filtration - water is passed through a series of fine filters, then activated carbon is used to filter out dissolved pollutants.

NH₃ is a bad smelling gas. It is vital to produce the nitrates used in fertilisers.

N₂ + 3H₂ 2NH₃

Reversible reaction so the reaction is done at 450°C with an Iron oxide catalyst and 200 atmospheres pressure. This ensures the reaction does not reverse back to the reactants

Made of a platinum or palladium catalyst in order to convert harmful gasses to safe gasses.

E.g. NOx converted no nitrogen and oxygen gasses

These supply plants with vital elements for growth so they can produce for us. These are Nitrogen (in the form of NO3^- (nitrate salts)), phosphorus (in the form of PO4^3-(phosphate)) and pottasium salts (k^+)

Rust (hydrated iron (III) oxide) affects most structures made of iron or steel and causes huge damage. It can be prevented by stopping the oxygen or water reaching the metal. This is done with paint, oil or grease, or covered in another metal (galvanising with zinc)

Iron + oxygen + Water -> hydrated iron (III) oxide

Burning hydrocarbon fuels

CH₄ + 2O₂ -> CO₂ + H₂O

Thermal decomposition of carbonates

CaCO₃ ->CaO + CO₂

Respiration in living cells

C₆H₁₂O₆ + O₂ -> CO₂ + H₂O