All practice pages/Interatomic theory/Elements
Element 6, a nonmetal
The element of life and of fuel. Its atoms link into chains and rings, building millions of compounds.
Period 2, group 14. The other nonmetals are tinted, and every cell opens its own article.
Carbon has 6 electrons, one for every proton, so the atom carries no charge. Below are the same 6 electrons written two ways.
1s² 2s² 2p²
Short form: [He] 2s² 2p², where [He] stands for the 2 electrons helium already has.
The simple form counts electrons shell by shell. The orbital form says which subshell each one sits in: s holds 2, p holds 6, d holds 10 and f holds 14. Shell 2 here is 2s² 2p², and 2 + 2 is 4.
Carbon sits in period 2 and has 2 shells. The period number counts the shells.
The outer shell holds 4 electrons. Those are the ones carbon can lose, gain or share, so they are the ones that decide what it bonds with. For a main-group element the group number gives that count: group 14 means 4.
Four valence electrons, halfway to a full shell, so carbon shares electrons instead of gaining or losing them. It forms four covalent bonds, including to other carbon atoms in chains, rings, and double and triple bonds.
About 0.02% of the crust by mass, mostly locked in limestone, chalk and marble as carbonates. It is in coal, oil and natural gas, in the air as carbon dioxide, and in every living thing: about 18% of your body by mass. Diamond and graphite also occur naturally.
Known since prehistory as charcoal and soot. Antoine Lavoisier listed it as an element in 1789, and in 1797 Smithson Tennant showed that burning diamond gives nothing but carbon dioxide. The name comes from the Latin carbo, charcoal. A third form, the soccer-ball-shaped C₆₀ molecule, was discovered in 1985.
Coal, oil and natural gas supply most of the world's energy. Coke made from coal turns iron ore into iron, and a little carbon turns iron into steel. Graphite makes pencil leads, lubricants and battery electrodes; diamond cuts and drills; activated charcoal filters water and air; and carbon fiber makes stiff, light bike frames and aircraft parts.