Carbon (C) is a chemical element with atomic number 6. It's one of the most abundant elements on Earth.

Carbon is a necessary building block of all known lifeforms, everything from animals and plants to bacteria and fungus.

The carbon atom's four valence electrons (outer shell electrons) allows the atoms to arrange themselves and bond in various different ways, creating structures with very different attributes. These different structures are called allotropes. Two of the most well known carbon allotropes include diamond and graphite.

The most abundant carbon isotope is ¹²C (6 protons and 6 neutrons), but another well-known isotope is ¹⁴C (6 protons, 8 neutrons) whose radioactive properties and predictable half-life allows for accurate archeological dating ("radiocarbon dating"). Simply put, the less ¹⁴C found in a dead plant or animal, the longer ago it died.

Carbon is one of the few elements whose name can be spelled using element symbols: Ca - Rb - O - N.