Air is a mixture of gases. The gas that makes up the majority of air – about 80 per cent, is nitrogen, which is a fairly inert gas. Air also contains argon, another inert gas, water vapour, oxygen, carbon dioxide and some other gases, which are only present in very tiny amounts.
The most useful gas in air is probably oxygen because it is this gas that is so vital to living things that respire aerobically. This is all animals, plants, bacteria and single celled organisms that live in the air and water. There are only a few species of lower invertebrates, bacteria and algae that can even survive in environments that are completely or even partially anoxic (without oxygen).
Carbon dioxide is thought of as a bad component of air, as it contributes to the greenhouse effect around the Earth that is leading to global warming. However, it is the increase in carbon dioxide caused by human activity that is the problem, not the gas itself. Carbon dioxide is actually necessary for plants to photosynthesise – and without this process, no animals would be able to survive.
The most useful gas in air is probably oxygen because it is this gas that is so vital to living things that respire aerobically. This is all animals, plants, bacteria and single celled organisms that live in the air and water. There are only a few species of lower invertebrates, bacteria and algae that can even survive in environments that are completely or even partially anoxic (without oxygen).
Carbon dioxide is thought of as a bad component of air, as it contributes to the greenhouse effect around the Earth that is leading to global warming. However, it is the increase in carbon dioxide caused by human activity that is the problem, not the gas itself. Carbon dioxide is actually necessary for plants to photosynthesise – and without this process, no animals would be able to survive.