6CCarbon12.011 u
Carbon (C)
Carbon is a nonmetal with atomic number 6, in period 2 and group 14 of the periodic table. Its atomic mass is 12.011 u and its electron configuration is [He] 2s² 2p². Solid at 25 °C.
Key facts
| Atomic number | 6 |
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| Atomic mass | 12.011 u |
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| Category | Nonmetal |
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| Period | 2 |
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| Group | 14 |
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| Block | p |
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| Electron configuration | [He] 2s² 2p² |
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| Electrons per shell | 2, 4 |
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| Electronegativity (Pauling) | 2.55 |
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| Oxidation states | −4, −3, −2, −1, +1, +2, +3, +4common in bold |
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| State at 25 °C | Solid |
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| Melting point | 3823 K3549.85 °C |
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| Boiling point | 4098 K3824.85 °C |
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| Density | 2.26 g/cm³ |
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Atomic properties
| First ionization energy | 11.26 eV |
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| Electron affinity | 121.9 kJ/mol |
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| Atomic radius | 67 pm |
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| Covalent radius | 76 pm |
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| Van der Waals radius | 170 pm |
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| Common ions | C⁴⁺, C⁴⁻ |
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| Protons, neutrons, electrons | 6, 6, 6 |
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Physical and thermal properties
| Molar volume | 5.29 cm³/mol |
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| Heat of fusion | 105 kJ/mol |
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| Heat of vaporization | 715 kJ/mol |
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| Specific heat | 710 J/(kg·K) |
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| Thermal conductivity | 140 W/(m·K) |
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| Thermal expansion | 7.1 × 10⁻⁶ K⁻¹ |
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| Mohs hardness | 0.5 |
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| Young’s modulus | --- |
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| Crystal structure | Simple hexagonal |
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| Magnetic type | Diamagnetic |
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Identification and history
| CAS number | 7440-44-0 |
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| Latin name | Carbonium |
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| Discovered by | Known since antiquity |
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| Named by | Antoine Lavoisier · 1789 |
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Natural isotopes
| Isotope | Mass (u) | Abundance |
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| 12C | 12 | 98.94 % |
| 13C | 13.003355 | 1.06 % |
Data checked against PubChem (NIH), IUPAC, the NIST Atomic Spectra Database and the IAEA (NUBASE and AME), the same data you see in the app.
A dash (---) means there is no reliable published measurement. The app never makes one up.
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Periodic Table