Forms of pure carbon include

Carbon is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up about 0.025 percent of Earth's crust. Monomers and Polymers of Carbon: Because of carbon's ability to form so many covalent bonds, it often forms polymers. A polymer is a large molecule that consists of many smaller molecules joined together by covalent bonds. The smaller molecules are called monomers. (The prefix mono- means “one” and the prefix poly- means... Show more

Carbon is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up about 0.025 percent of Earth's crust.

Monomers and Polymers of Carbon: Because of carbon's ability to form so many covalent bonds, it often forms polymers. A polymer is a large molecule that consists of many smaller molecules joined together by covalent bonds. The smaller molecules are called monomers. (The prefix mono- means “one” and the prefix poly- means “many.”)

Polymers may consist of just one type of monomer or of more than one type. Polymers are a little like strings of beads. Like monomers making up a polymer, the beads in a string may be all the same or different from one another.    
Many polymers occur naturally. Other polymers are synthetic. This means that they are produced in labs or factories. Synthetic polymers are created in synthesis reactions in which monomers bond together to form much larger compounds.

Plastics are examples of synthetic polymers. A very common type of plastic is polythene (also called polyethylene). It consists of repeating monomers of ethene (C2H4). This plastic is used to make plastic milk jugs and grocery bags, among many other uses.    

Show less