Air is a mixture of gases: roughly 78% nitrogen, 21% oxygen, 0.03–0.04% carbon dioxide, plus variable amounts of water vapour, inert gases and dust particles.
- Active part: the reactive component of air — oxygen.
- Inactive part: the rest — nitrogen, carbon dioxide, the noble gases (argon, helium, neon), water vapour and dust.
Oxygen supports breathing and respiration, supports burning, and contributes to soil fertility as a soil nutrient.
Air Pollution
Air pollution is the release of harmful gases or particles (pollutants) into the atmosphere. Common sources include incomplete combustion of fuels like petrol, diesel, kerosene, firewood or coal; exhaust from vehicles, aircraft and ships; chemical waste from industry; poisonous volcanic gases; and CFCs released from aerosol cans.
