French physicist René Antoine Ferchault Reaumur (1683-1757) believed carbon might be an element.
The name they used, carbone, is based on the earlier Latin term for charcoal, charbon. Allotropes are forms of an element with different physical and chemical properties.
Carbon occurs extensively in all living organisms as proteins, fats, carbohydrates (sugars and starches), and nucleic acids.
Humans have been aware of carbon since the earliest of times. The black color of smoke is caused by unburned specks of carbon.
For example, diamond is the hardest natural substance known. The Mohs scale is a way of expressing the hardness of a material. The melting point of diamond is about 3,700°C (6,700°F) and its boiling point is about 4,200°C (7,600°F). On the other hand, graphite is a very soft material. Sublimination is the process by which a solid changes directly to a gas when heated, without first changing to a liquid.
Its density is about 1.5 to 1.8 grams per cubic centimeter.
Carbon also occurs in a form, discovered only recently, known as fullerenes or buckyballs.