Carbon Facts

Carbon Chemical & Physical Properties

Diamond is one form of pure carbon.
Diamond is one form of pure carbon. USGS

Carbon Basic Facts

Atomic Number: 6

Symbol: C

Atomic Weight: 12.011

Discovery: Carbon exists free in nature and has been known since prehistoric time.

Electron Configuration: [He]2s22p2

Word Origin: Latin carbo, German Kohlenstoff, French carbone: coal or charcoal

Isotopes: There are seven natural isotopes of carbon. In 1961 the International Union of Pure and Applied Chemistry adopted the isotope carbon-12 as the basis for atomic weights.

Properties: Carbon is found free in nature in three allotropic forms: amorphous (lampblack, boneblack), graphite, and diamond. A fourth form, 'white' carbon, is thought to exist. Diamond is one of the hardest substances, with a high melting point and index of refraction.

Uses: Carbon forms numerous and varied compounds with limitless applications. Many thousands of carbon compounds are integral to life processes. Diamond is prized as a gemstone and is used for cutting, drilling, and as bearings. Graphite is used as a crucible for melting metals, in pencils, for rust protection, for lubrication, and as a moderator for slowing neutrons for atomic fission. Amorphous carbon is used for removing tastes and odors.

Element Classification: Non-Metal

Carbon Physical Data

Density (g/cc): 2.25 (graphite)

Melting Point (K): 3820

Boiling Point (K): 5100

Appearance: dense, black (carbon black)

Atomic Volume (cc/mol): 5.3

Ionic Radius: 16 (+4e) 260 (-4e)

Specific Heat (@20°C J/g mol): 0.711

Debye Temperature (°K): 1860.00

Pauling Negativity Number: 2.55

First Ionizing Energy (kJ/mol): 1085.7

Oxidation States: 4, 2, -4

Lattice Structure: Diagonal

Lattice Constant (Å): 3.570

Crystal Structure: hexagonal

Electronegativity: 2.55 (Pauling scale)

Atomic Radius: 70 pm

Atomic Radius (calc.): 67 pm

Covalent Radius: 77 pm

Van der Waals Radius: 170 pm

Magnetic Ordering: diamagnetic

Thermal Conductivity (300 K) (graphite): (119–165) W·m−1·K−1

Thermal Conductivity (300 K) (diamond): (900–2320) W·m−1·K−1

Thermal Diffusivity (300 K) (diamond): (503–1300) mm²/s

Mohs Hardness (graphite): 1-2

Mohs Hardness (diamond): 10.0

CAS Registry Number: 7440-44-0

References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952)

Quiz: Ready to test your carbon facts knowledge? Take the Carbon Facts Quiz.

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