Carbon

Carbon (from the Latin carbo for "coal") is a chemical element (atomic number 6). It has been identified as an element since ancient times. At normal temperatures and pressures, it is a non-metallic black solid. It combines readily with oxygen to form carbon dioxide. In the absence of the necessary amount of oxygen, it instead forms carbon monoxide.
Carbon is in all living cells and is found in almost every molecule in biology. By definition, "organic chemistry" encompasses all molecules that contain carbon. It's the backbone of most foods, being one of the primary components of carbohydrates and fat.
A rare radioactive isotope of carbon, Carbon-14, is used in nuclear medicine as it can be traced through the metabolism of both human cells and bacteria.
Activated charcoal is a form of carbon specially treated to have a very high surface area. It's used to treat patients who have ingested a toxin.
Carbon at Wikipedia
Category:Biology