Carbon (C)

Graphite is black, diamond is transparent

Carbon is the backbone of all known life, forming diamonds, graphite, and every organic molecule, and with four valence electrons enabling sp, sp², and sp³ hybridization, carbon forms the largest variety of compounds of any element. It exists as diamond, graphite, graphene, fullerene, and nanotubes.

Key metrics

Density2.27g/cm³

Melting point3,823K

Boiling point4,300K

Electronegativity2.55Pauling

Discovery

3750discovered

Discovered by: Ancient
Reactivity profile: Forms strong covalent bonds
Reactivity: Medium
Bonding: Covalent

Electron configuration

\textcolor{#6b7280}{[He]}\; \textcolor{#ef4444}{2_{s}^{2}}\; \textcolor{#3b82f6}{2_{p}^{2}}

[He] 2s2 2p2

Wave function

\Psi_{\text{C}} \approx \frac{1}{\sqrt{6!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_6(\mathbf{r}_6) \right|

Probability density $|\Psi|^2$ across the C valence shell.

Crystal structure

Diamond Cubic

Lattice constantsa = 1.00

Cell anglesα = β = γ = 90°

Coordination number4

Atoms per cell8

Atomic packing factor0.34

Physical properties

Atomic radius: 67 pm
Ionization energy: 1086 kJ/mol
Electron affinity: 122 kJ/mol
Crystal structure: Graphite: simple Hexagonal, Diamond: Cubic

Oxidation states

-4+2+4

Acid/base

Neutral

Strongly acidicStrongly basic

State at 25 °CSolid

3823 K4300 K298 K

Emission spectrum

4 transitions

380450500550600650700780

VioletBlueGreenYellowRed

426.7nmC II (blue)Violet100%

514.5nmC I (green)Green50%

589.0nmC IYellow80%

657.8nmC I (red)Red60%

Dominant line 426.7 nmRange 427–658 nmTransitions 4