Graphite is one of the softest known materials while diamond is one of the hardest. Carbon has the unique ability to link with other carbon atoms to form complex chains and rings. This property leads to an almost infinite number of carbon compounds, the most common being those containing carbon and hydrogen. In combination, carbon is found as carbon dioxide in the atmosphere of the earth and dissolved in all natural waters. Coal, petroleum, and natural gas are chiefly hydrocarbons.
Carbon is unique among the elements in the vast number of variety of compounds it can form.
Carbon is also the basis for atomic weights. Please understand that this site is done as Chemistry 11 Project. Do not take it seriously.