Carbon (C)
Carbon is element 6, a reactive nonmetal in period 2, group 14 of the periodic table. At room temperature it is a solid.
Electron configuration [He] 2s2 2p2
Electrons per shell 2, 4
Carbon data
| Atomic number | 6 |
|---|---|
| Symbol | C |
| Atomic mass | 12.011 u |
| Category | Reactive nonmetal |
| Group | 14 |
| Period | 2 |
| Block | p |
| State at 25 °C | solid |
| Melting point | 3823 K (3549.9 °C) |
| Boiling point | 4300 K (4026.9 °C) |
| Density | 2.26 g/cm³ |
| Electronegativity (Pauling) | 2.55 |
| Atomic radius | 77 pm |
| 1st ionization energy | 1087 kJ/mol |
| Electron affinity | -154 kJ/mol |
| Oxidation states | -4, -3, -2, -1, +1, +2, +3, +4 |
| Common ion charge | 4+, 4− |
| Discovered | Known since antiquity |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through carbon’s configuration and its ions →
Where carbon sits
Carbon belongs to the reactive nonmetals. Its Pauling electronegativity of 2.55 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.
Carbon FAQ
What is the electron configuration of carbon?
Carbon (Z = 6) has the configuration 1s2 2s2 2p2. In noble-gas shorthand that is [He] 2s2 2p2.
How many valence electrons does carbon have?
4 (outer shell (n = 2)).
What is the atomic mass of carbon?
The standard atomic weight of carbon is 12.011 u, so one mole weighs 12.011 g.
Is carbon a metal?
No. Carbon is a reactive nonmetal.
What is the charge of a carbon ion?
Carbon most commonly forms C4+ or C4−.