Carbon
Carbon is the chemical backbone of life, capable of forming more known compounds than every other element combined thanks to its ability to bond with itself in long chains, rings, and sheets. It's been known and used since prehistoric times in forms like charcoal and soot, long before anyone understood it as a distinct chemical element.
- Group · Period
- 14 · 2
- At room temp
- solid
- Melts at
- 3823 K
- Density
- 2.267 g/cm³
- Discovered
- Ancient
Uses
Carbon’s most fundamental role is biological: it forms the structural backbone of proteins, DNA, carbohydrates, and every other organic molecule that makes up living things. Industrially, carbon in the form of coal and coke has powered steelmaking and energy production for centuries, while activated carbon’s huge internal surface area makes it excellent at filtering water and air by trapping impurities.
Carbon’s different structural forms give it very different jobs: graphite is used in pencils, lubricants, and battery electrodes, while diamond’s extreme hardness makes it valuable for cutting and grinding tools as well as jewelry. More recently, engineered carbon materials like carbon fiber — woven strands of nearly pure carbon bonded into a strong, lightweight composite — have become essential in aerospace, automotive, and sporting goods manufacturing.
History
Carbon has no single discoverer, since forms of it — charcoal, soot, and natural diamond — have been recognized and used by humans since prehistoric times, long predating any scientific understanding of elements. Its identity as a true chemical element was established in the late 1770s and 1780s by French chemist Antoine Lavoisier, who demonstrated through careful combustion experiments that diamond and charcoal both burned to form the same gas, carbon dioxide, proving they were different forms of one underlying substance.
Fun facts
- Carbon forms more known compounds than all other elements put together, which is the entire reason organic chemistry exists as its own field of study.
- Diamond and graphite are both pure carbon, but their wildly different properties — diamond's hardness versus graphite's softness and conductivity — come entirely from how the atoms are arranged.
- Radiocarbon dating uses the slow, predictable decay of carbon-14 to determine the age of organic remains, allowing scientists to date items up to roughly 50,000 years old.
Frequently asked questions
Why can carbon form so many different compounds?
Carbon has four electrons available for bonding, and it can share them to form strong, stable bonds not just with other elements but with other carbon atoms — chaining together into long strings, branching structures, rings, and sheets. That self-bonding ability, called catenation, is unusually strong in carbon and is the foundation of organic chemistry.
What's actually different between diamond and graphite?
Both are pure carbon, but the atoms are arranged differently. In diamond, each carbon atom bonds tightly to four neighbors in a rigid 3D lattice, making it extremely hard and electrically insulating. In graphite, carbon atoms form flat, loosely stacked sheets that slide past each other easily, making it soft, slippery, and a decent conductor of electricity.
Who discovered carbon, if it's been known since ancient times?
No one person gets credit — carbon in forms like charcoal and soot has been used since prehistory, long before the idea of a chemical element existed. It was French chemist Antoine Lavoisier who, in the late 1700s, showed through careful experiments that diamond, charcoal, and soot were all forms of the same underlying element.
Compounds
29 notable compounds containing C
- BaCO3mineral
Barium carbonate
A dense white powder, also found naturally as the mineral witherite, once widely used as a rodenticide because it dissolves in stomach acid but not in water.
Used for: Rat poison and ingredient in specialty ceramic glazes and optical glass
- C7H5BiO4pharmaceutical
Bismuth subsalicylate
A pale yellow, water-insoluble organobismuth compound that coats and soothes the stomach lining while its salicylate portion provides mild anti-inflammatory action.
Used for: Active ingredient in over-the-counter upset-stomach remedies like Pepto-Bismol
- CaCO3mineral
Calcium carbonate
An ionic carbonate salt found naturally as limestone, chalk, and marble, and as the structural material of seashells and coral.
Used for: Antacid tablets, cement and construction, calcium supplement
- CO2gas
Carbon dioxide
A linear molecule produced by respiration and combustion, and the main greenhouse gas driving global climate change.
Used for: Carbonating beverages, fire extinguishers, dry ice refrigeration
- COgas
Carbon monoxide
A colorless, odorless gas held together by a strong triple bond, formed from incomplete combustion and dangerous because it binds hemoglobin far more tightly than oxygen does.
Used for: Industrial reducing agent in metal smelting, syngas feedstock
- Cs2CO3salt
Cesium carbonate
A hygroscopic white salt widely used as a mild, highly soluble base in organic and pharmaceutical synthesis.
Used for: Base reagent in organic synthesis, including palladium-catalyzed couplings
- CHCl3organic
Chloroform
A dense, sweet-smelling liquid in which three of methane's hydrogens are replaced by chlorine atoms. It was historically used as a surgical anesthetic before its toxicity was well understood.
Used for: Industrial solvent and precursor in refrigerant manufacturing
- C2H6Oorganic
Ethanol
A simple alcohol whose polar hydroxyl group lets it mix freely with water while its hydrocarbon chain keeps it flammable and volatile.
Used for: Alcoholic beverages, fuel additive, disinfectant and solvent
- C6H12O6organic
Glucose
A six-carbon simple sugar that exists mainly as a ring-shaped molecule in solution, and the primary energy source for most living cells.
Used for: Cellular energy metabolism, IV fluids, food and beverage sweetening
- HfCindustrial
Hafnium carbide
An extremely hard, grey ceramic with one of the highest melting points of any known binary compound, giving it exceptional resistance to extreme heat.
Used for: Ultra-high-temperature coatings for rocket nozzles and hypersonic vehicle surfaces
- La2(CO3)3pharmaceutical
Lanthanum carbonate
An insoluble lanthanum salt taken orally to bind excess dietary phosphate in the gut, passing through the digestive tract largely unabsorbed.
Used for: Phosphate-binding medication for kidney dialysis patients
- Li2CO3salt
Lithium carbonate
A white ionic salt that is one of the few practical sources of soluble lithium ions, produced from lithium-bearing brines and minerals.
Used for: Mood-stabilizing medication for bipolar disorder
- Cu2CO3(OH)2mineral
Malachite
A bright green basic copper carbonate mineral that forms naturally where copper ores weather, and is the same compound responsible for the green patina that develops on aged copper and bronze.
Used for: Ornamental stone and green pigment; ore of copper
- CH4organic
Methane
The simplest hydrocarbon, a tetrahedral molecule of one carbon bonded to four hydrogens, and the main component of natural gas.
Used for: Natural gas fuel for heating and electricity generation
- CH3Brorganic
Methyl bromide (bromomethane)
A colorless, odorless gas once widely used as an agricultural fumigant, now heavily restricted because it depletes stratospheric ozone.
Used for: Soil and commodity fumigant, largely phased out under the Montreal Protocol
- Mo(CO)6reagent
Molybdenum hexacarbonyl
A white, volatile solid in which a molybdenum atom is surrounded octahedrally by six carbon monoxide ligands, a classic and widely studied organometallic compound.
Used for: Catalyst and vapor-deposition precursor for depositing molybdenum films
- NbCindustrial
Niobium carbide
An extremely hard, high-melting-point ceramic compound often added to tungsten carbide cutting tools to refine their grain structure.
Used for: Grain-refining additive in cemented carbide cutting tools
- Pd(OAc)2reagent
Palladium(II) acetate
An orange-brown, soluble palladium salt that is one of the most widely used catalysts in modern organic chemistry, central to many carbon-carbon bond-forming reactions.
Used for: Catalyst for Heck, Suzuki, and other palladium-catalyzed cross-coupling reactions
- (C2H3Cl)norganic
Polyvinyl chloride
A synthetic polymer built from repeating vinyl chloride units, valued for being durable, lightweight, and resistant to weathering. It's one of the most widely produced plastics in the world.
Used for: Plumbing pipes, window frames, cable insulation, flooring
- Rb2CO3salt
Rubidium carbonate
A hygroscopic white salt used chiefly as a starting material for other rubidium compounds and in specialty high-index optical glass.
Used for: Additive in high-refractive-index optical glass and fiber optics
- SiCindustrial
Silicon carbide
An extremely hard covalent network solid with a diamond-like lattice, rare in nature but produced in bulk synthetically.
Used for: Abrasives and cutting tools, semiconductor substrates, brake discs
- NaHCO3salt
Sodium bicarbonate
A mildly alkaline ionic salt known as baking soda, which releases carbon dioxide gas when it reacts with acids or heat.
Used for: Baking leavening agent, antacid, fire extinguisher and cleaning agent
- Na2CO3salt
Sodium carbonate
An alkaline ionic salt known as soda ash or washing soda, historically extracted from the ashes of certain plants.
Used for: Glass manufacturing, water softening, laundry detergent
- SrCO3mineral
Strontium carbonate
A white, poorly water-soluble compound found naturally as the mineral strontianite, once the key ingredient in red phosphors and color television glass.
Used for: Ceramic ferrite magnets and pyrotechnic red colorant
- TaCindustrial
Tantalum carbide
An extremely hard, brownish-grey ceramic with one of the highest melting points of any known material, making it valuable wherever extreme heat and wear resistance are required.
Used for: Wear-resistant coatings on cutting tools and ultra-high-temperature components
- Ru3(CO)12reagent
Triruthenium dodecacarbonyl
An orange cluster compound built from three ruthenium atoms bridged by carbon monoxide ligands, widely studied as a catalyst and a building block for other ruthenium clusters.
Used for: Catalyst precursor in organic synthesis and organometallic research
- WCindustrial
Tungsten carbide
A dense, extremely hard grey compound, nearly as stiff as diamond, usually sintered with a cobalt binder into tough composite tooling material.
Used for: Cutting tools, mining drill bits, and scratch-resistant jewelry
- RhCl(PPh3)3reagent
Wilkinson's catalyst
A landmark rhodium complex bearing three triphenylphosphine ligands that catalyzes the hydrogenation of alkenes under mild conditions, a discovery that helped found modern homogeneous catalysis.
Used for: Homogeneous catalyst for hydrogenating alkenes in organic synthesis
- ZrCindustrial
Zirconium carbide
An extremely hard, refractory ceramic with one of the highest melting points known among simple compounds, giving it excellent resistance to extreme heat.
Used for: Ultra-high-temperature ceramic coatings for aerospace and cutting tools
Isotopes
14 known isotopes
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| Isotope | Natural abundance | Half-life | Decay mode | Mass excess | Binding energy / nucleon | Decay width |
|---|---|---|---|---|---|---|
| C-12 stable | 98.94% | Stable | — | 0 keV | 7,680.14 keV | — |
| C-13 stable | 1.06% | Stable | — | 3,125.01 keV | 7,469.85 keV | — |
Show all 14 isotopes
| C-8 | — | 130 keV | Two-proton emission (100%) | 35,064.27 keV | 3,101.52 keV | 1.30 × 105 eV |
| C-9 | — | 126.5 ms | Electron capture / beta-plus decay (100%), Beta-plus, proton emission (62%), Beta-plus, alpha emission (37.9%) | 28,910.97 keV | 4,337.42 keV | 3.61 × 10-15 eV |
| C-10 | — | 19.290 s | Electron capture / beta-plus decay (100%) | 15,698.67 keV | 6,032.04 keV | 2.37 × 10-17 eV |
| C-11 | — | 20.364 m | Electron capture / beta-plus decay (100%) | 10,649.4 keV | 6,676.46 keV | 3.73 × 10-19 eV |
| C-14 | — | 5700 Y | Beta-minus decay (100%) | 3,019.89 keV | 7,520.32 keV | 2.54 × 10-27 eV |
| C-15 | — | 2.449 s | Beta-minus decay (100%) | 9,873.15 keV | 7,100.17 keV | 1.86 × 10-16 eV |
| C-16 | — | 0.747 s | Beta-minus decay (100%), Beta-minus, neutron emission (99%) | 13,694.13 keV | 6,922.05 keV | 6.11 × 10-16 eV |
| C-17 | — | 193 ms | Beta-minus decay (100%), Beta-minus, neutron emission (26%) | 21,031.88 keV | 6,558.03 keV | 2.36 × 10-15 eV |
| C-18 | — | 92 ms | Beta-minus decay (100%), Beta-minus, neutron emission (31.5%) | 24,919.27 keV | 6,426.13 keV | 4.96 × 10-15 eV |
| C-19 | — | 46.3 ms | Beta-minus decay (100%), Beta-minus, neutron emission (47%), B-2N (7%) | 32,413.75 keV | 6,118.27 keV | 9.85 × 10-15 eV |
| C-20 | — | 16.3 ms | Beta-minus decay (100%), Beta-minus, neutron emission (65%), B-2N (18.6%) | 37,503.57 keV | 5,961.44 keV | 2.80 × 10-14 eV |
| C-22 | — | 6.1 ms | Beta-minus decay (100%), Beta-minus, neutron emission (61%), B-2N (37%) | 53,611.2 keV | 5,421.08 keV | 7.48 × 10-14 eV |