On August 1, 1774, British chemist Joseph Priestley conducted an experiment, focusing sunlight on oxidized mercury in a glass tube, and found that oxidized mercury would release a The gas, which Priestley named "anti-inflammatory air".
Later he discovered that candles would burn more vigorously in "anti-inflammatory air", and when mice were put into a container containing this gas, the mice would breathe more actively and survive longer than in A container containing the same volume of air lasts longer, this is the discovery of oxygen. Before the emergence of life, the oxygen content in the earth's atmosphere was very little, and the emergence of life had a great impact on the atmospheric environment.
Currently, the oxygen content is the highest on the earth, accounting for about 46%, followed by silicon, which accounts for 28%, and the iron element, which only accounts for 6%. However, the oxygen content in nature is not the highest on the earth. Only 21 are present in the atmosphere. Oxygen is an essential condition for aerobic organisms. As we all know, all living things, including humans, are inseparable from oxygen.
First of all, our breathing is inseparable from oxygen. The red blood cells in the body transport oxygen throughout the body to allow various organs to work normally. Then they send carbon dioxide to the lungs, exhale, and then complete one breath. Moreover, according to research by scientists, the growth of animals is related to the oxygen content in the air. Oxygen is like a kind of energy of the earth, maintaining the safety of life.
Even though most life on earth cannot do without oxygen, any substance has two sides, and more oxygen is not always better.
Remember the giant creatures before life appeared? For example, the small dragonflies we see now actually used to have extremely high oxygen content, so even small dragonflies were giants. High oxygen levels do provide better energy for organisms to breathe, and organisms can grow to huge sizes.
However, the oxygen content in the atmosphere still needs to have a suitable range. Within that range, it is beneficial to the development of many species on the earth. Excessive oxygen is toxic to us. If excessive oxygen is inhaled for a long time, it is likely to cause chest pain, nausea, vomiting, and even blindness.
And the increase in oxygen content will make many things that are not flammable now very flammable. For example, plastics will burn very easily as long as they are in places with high oxygen content. Of course, there are many items that will burn more vigorously if the oxygen content is increased within the original combustible oxygen content range. Therefore, if the oxygen content increases without limit, the result will be mass extinction of organisms.