What Is Called “Oxygen”?
Often we read about something that man “could not live without”. One thing that is absolutely essential to life is oxygen. A human being can not live without oxygen, beyond a few minutes.
Oxygen is the most essential and plentiful element in nature. It makes nearly half of the earth’s crust and one-fifth of the air breathed into the lungs. The red corpuscles constantly carry oxygen to the body cells in a stream. In the body, it burns food and generates heat, which is required for maintaining the human body.
Oxygen combines easily with most elements, and this process is called oxidation. When this process is quick, combustion takes place and a lot of heat is released. With the rise in temperature, flames appear. So at one end, there is combustion, fire is produced due to fast oxidation and at the other end, the oxidation burns food to keep life going. Slow oxidations with oxygen in the air are found commonly – in rusting of iron, the paint dries, alcohol is changed into vinegar.
The air that we breathe is a mixture of nitrogen and oxygen. Air can be cooled and liquefied. This temperature is about minus 180 degrees centigrade. With a slight rise in temperature, the liquid air warms up and boils. Nitrogen boils off first and oxygen remains. Many lives have been saved by giving people oxygen to help them breathe easily.