ABSTRACT
The atmosphere plays a major part in the various cycles of nature, including the water cycle, carbon cycle, and nitrogen cycle. It is stratified with altitude with respect to temperature. The approximate composition of dry air is, by volume at sea level, nitrogen 78%, oxygen 21%, argon 0.93%, and carbon dioxide 0.03%, together with very small amounts of numerous other constituents. Nitrogen (N2) makes up the major portion of the atmosphere. Nitrogen is part of the earth’s atmosphere primarily because, over time, it has simply accumulated in the atmosphere and remained in place and in balance. Gaseous nitrogen is converted to a form usable by plants chiefly through the process of nitrogen fixation via the nitrogen cycle. Gaseous oxygen (O2) is vital to life as people know it. Water and carbon dioxide are common examples of compounds that contain oxygen, but there are countless others. All the elements, except the inert gases, combine directly with oxygen to form oxides.
