Carbon (C)
“One element, three personalities: pencil-soft black graphite, hardest-natural diamond and football-shaped fullerenes — every one of them pure carbon.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
Characteristics
- Tetravalent to the bone: four valence electrons let a carbon atom hold four strong covalent bonds at once, so it can build chains, rings and branches — the skeleton of every organic molecule.
- Champion of self-bonding (catenation): no other element links into such long, stable chains of itself, which is why millions of carbon compounds are known — more than all other elements combined.
- Allotropy at the extremes: diamond, the hardest natural material and an electrical insulator; graphite, soft enough to rub off on paper yet a good conductor; plus fullerenes, nanotubes and one-atom-thin graphene.
- The engine of life: proteins, fats, carbohydrates and DNA all stand on carbon backbones, and the slow decay of carbon-14 lets archaeologists read the age of ancient bones and wood.
A solid nonmetal of wildly different faces: sparkling, colourless diamond; black, flaky, slippery graphite; sooty charcoal powder; and nanoscale spheres and tubes. It never melts in an ordinary flame — at atmospheric pressure it skips the liquid state altogether and turns straight into vapour above 3,600 °C.
Where you meet it
✦ Uses
- Coke — coal stripped of its impurities — is charged into blast furnaces to snatch oxygen away from iron ore; the world’s steel, including every rafter in Dhaka, begins with coke.
- Graphite: the “lead” inside every pencil, the electrodes of arc furnaces and dry cells, and the neutron-slowing moderator at the heart of many nuclear reactors.
- Activated carbon — the black granules inside household water purifier cartridges — soaks up chlorine, pesticides and bad odours from drinking water.
- Diamond-tipped drill bits, saws and polishing paste for cutting glass, stone and concrete, and carbon-fibre frames for aircraft, racing bikes and badminton rackets that beat steel at a fraction of the weight.
◍ Everyday examples
- The pencil in a student’s geometry box writes with stacked sheets of graphene — pure carbon sliding off onto the page.
- Sugar, rice, dal, fish and cooking oil are all carbon-based foods; digestion merely reshuffles their carbon skeletons.
- The soot blackening the bottom of an aluminium degchi, or the charcoal glowing under a street kebab grill — everyday carbon at work.
History & name
Carbon has no single discoverer — charcoal, soot and wood smoke were humanity’s companions long before chemistry had a name. Indians were treasuring diamonds by the fourth century BCE, and graphite was being used for marking by the 1500s. In 1772 Antoine Lavoisier burned a diamond with a burning lens and showed that nothing came off but carbon dioxide — quietly proving that diamond and charcoal are the same element — and in 1789 he entered carbon in his historic list of the elements. The name comes straight from the Latin carbo, “charcoal”.