Carbon can form sharply different materials. Graphite is soft enough to write with, while diamond is used for cutting and drilling. Carbon also forms strongly bonded chains in organic molecules, connecting familiar substances such as plastics and fuels to the chemistry of life.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
Why can diamond cut materials that graphite cannot handle similarly?
Diamond, an elemental carbon structure
FOLLOW THIS RELATIONSHIP
Compare the carbon structures
Diamond and graphite contain carbon but arrange its bonding differently; the comparison holds elemental identity constant while changing the material's organization.
Explore the model (optional)
Spatial model
INTERACTIVE 3D64 visible sites
Diamond · a tetrahedral networkDrag to rotate · scroll or pinch to zoom
Four nearest neighbors form a tetrahedral environment. Rotate the network to see connections hidden by a flat projection.
What this representation means
Idealized crystal fragment. Spheres and spacing are schematic; cropped boundary sites have fewer displayed neighbors than interior sites.
Charcoal, graphite, and diamond were familiar in different settings before their shared elemental identity was established. In 1694, experiments showed that strongly heated diamond could disappear. Tennant later demonstrated that burning diamond produced carbon dioxide, supporting its identification as carbon. The history shifts attention from a substance's appearance to what its reaction products establish about composition.
1694
Diamond combustion investigated
Concentrated sunlight destroyed diamond in Averani and Targioni’s experiments.
1796
Carbon identity demonstrated
Tennant identified carbon dioxide produced by burning diamond.
Carbon occurs as elemental materials such as graphite and diamond, and in compounds including atmospheric carbon dioxide, , and organic matter. It therefore connects rocks, water, air, and living systems. Finding carbon in two places does not show that the same atoms traveled directly between them.
Carbon forms extensive networks and chains of bonds, giving rise to a large variety of compounds and elemental structures. Graphite and diamond illustrate sharply different properties despite sharing elemental composition. Explaining their behavior requires the arrangement of atoms and bonds, rather than only the symbol C.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
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Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
solid
293.15 K, 101.325 kPa
Melting point in K
3823 K
at standard pressure unless noted Graphite sublimes at standard pressure; the value is the triple-point melting temperature.
Boiling point in K
3915 K
101.325 kPa
Density in g/cm³
2.27 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa Value for graphite; diamond is 3.515 g/cm³.
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
2.55 Pauling
Pauling scale
First ionization energy in kJ/mol
1087 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
73 pm
single-bond covalent radius
Common oxidation states
-4, +2, +4
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
200 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year
Not recorded
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 2
C 2.55 Pauling · Carbon
Electronegativity across period 2. Exact values.
Li
0.98
Be
1.57
B
2.04
C
2.55
N
3.04
O
3.44
F
3.98
Electronegativity down group 14
C 2.55 Pauling · Carbon
Electronegativity down group 14. Exact values.
C
2.55
Si
1.9
Ge
2.01
Sn
1.96
Pb
2.33
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
