After reading this term paper you will learn about the composition of oxygen cycle present in the atmosphere.
The sequence in which oxygen from the atmosphere is used by organisms and eventually released back into the atmosphere through photosynthesis is called as oxygen cycle.
1. Oxygen makes up 21 percent of the air. It is an essential constituent of carbohydrates, proteins, fats and nucleic acids.
2. Oxygen is found in air, in combined form as carbon dioxide, and in the earth’s crust as carbonates, sulphates and nitrates.
3. Plants and animals use atmospheric oxygen during respiration and release the same during photosynthesis.
4. Fossil fuels require oxygen for combustion.
5. The ozone layer is present in the stratosphere, one of the layers of the atmosphere. Each molecule of ozone is made up of three oxygen atoms. The ozone layer prevents harmful radiations from reaching the earth’s surface, where they might damage life forms.
Ozone is a natural gas composed of three atoms of oxygen. Its chemical formula is O3. It is blue in color and has a strong odor. Normal oxygen (O2), which we breathe, has two oxygen atoms and is colorless and odorless.
The air is full of gases reacting with each other, even though our eyes do not see. When UV light strikes (Oxygen) O, molecules, they split into two individual O atoms — O and O. When one of the O atoms combine with O2 molecule, ozone (O3) is created.
The rays from the sun contain Ultra Violet Rays (UV Rays). UV rays are not all bad as they are good source of Vitamin D. But too much of it is very dangerous. Manufacturing activities since the industrial revolution have caused a disturbance in the atmosphere and opened up for more UV rays to come through to the earth. There have been serious consequences, and potentially it can get worse if we do not act responsibly.
Industries that manufacture things like insulating foams, solvents, soaps, cooling things like air conditioners, refrigerators and ‘take-away’ containers use something called chlorofluorocarbons (CFCs). Ultra violet radiation from the sun breaks up these CFCs. The breaking up action releases Chlorine atoms. Chlorine atoms react with ozone, starting a chemical cycle that destroys the ozone in that area.