Composition of air

• 78% Nitrogen

• 21% Oxygen

• 1% Noble gases ( argon)

• 0.03% Carbon dioxide

Uses of air

• helium is used to fill balloons, argon is used in tungsten light bulbs, krypton is used in lasers for eye surgery

• Oxygen is used in steel making, welding and in breathing apparatus

• Nitrogen is used in food packaging, the production of ammonia and in the production of silicon chips

• Carbon dioxide is used for photosynthesis

• Oxygen for breathing

• Oxygen for respiration

• Oxygen for combustion

Investigating the percentage of oxygen in air

• The percentage of oxygen in air can be investigated by passing a known quantity of air over a metal

• The oxygen in the air will react with the metal, forming a metal oxide

• The oxygen will be removed from the air and the volume of the air with the oxygen removed can be measured.

• Steps:

1.Heat the copper using a Bunsen burner

2.Push the plunger of the syringe containing air

3.Push the air back from the now filled plunger to the other plunger

4.Repeat this several times for about 3 minutes

5.The copper will turn black as copper reacts with the oxygen in the air and copper oxide is produced

6.Allow the apparatus to cool

7.Ensure all the gas is in one syringe and record the volume of gas

Air pollution

1. Carbon dioxide

• Adverse effects: increases global warming, which leads to climate change

2. Carbon monoxide

• Adverse effects: toxic, combining with haemoglobin in the blood and prevents it from carrying oxygen

3.Methane

• Adverse effects: increases global warming, which leads to climate change

4.Oxides of nitrogen

• Adverse effects: Produces photochemical smog

• Dissolves in rain to form acid rain

• Pollutes crops and water supplies

• irritates lungs, throats and eyes and causes respiratory problems.

5.Sulfur dioxide

• Adverse effects: dissolves in rain to form acid rain with similar effects as the acid rain caused by oxides of nitrogen

Carbon cycle

• Photosynthesis

• Decomposition

• Respiration

• Combustion.

Greenhouse effect

• The greenhouse effect is the way in which heat is trapped close to Earth's surface by “greenhouse gases' contributing to Global warming.

• gases like carbon dioxide, methane and CFCs are increasing global warming.