Abundance Of Carbon The black numbers indicate how much carbon is stored in various reservoirs, in billions tonnes. The purple numbers indicate how much carbon moves between reservoirs each year.

It is present in very small amount (0.02%) of the earth's crust. It ranks 17^th in the order of abundance in earth's crust. In nature, carbon occurs in free state as well as in combined state. In free state it is found as coal, diamond, graphite and fullerenes. In combined form, carbon occurs as:

• Mineral carbonates.
• Oxides of carbon.
• Organic compounds.
• Petroleum and Natural Gas.
• Natural waters.
• All living things.

Organic chemistry was redefined as the study of carbon compounds, regardless of their origin. Most naturally occurring organic compounds are produced by organisms, and these molecules represent a diversity and range of complexity unrivaled by inorganic compounds. However, the same rules of chemistry apply to inorganic and organic molecules alike. The foundation of organic chemistry is not some intangible life force, but the unique chemical versatility of the element carbon.