Carbon
Carbon is a chemical element with the symbol C and atomic number 6. It has a standard atomic weight of 12.011, sits in period 2 and group 14, and is classified as a reactive nonmetal.
Properties
| Symbol | C |
|---|---|
| Atomic number | 6 |
| Standard atomic weight | 12.011 |
| Category | Reactive nonmetal |
| Group | 14 |
| Period | 2 |
| Electron configuration | [He] 2s2 2p2 |
| Outer-shell electrons | 4 |
The figure of 12.011 is a conventional value, because IUPAC publishes an interval for this element rather than a single weight. For elements like this one the fourth digit carries real uncertainty, because the isotopic composition varies measurably between natural sources — so quoting eight digits would overstate what is known.
Compounds containing carbon
383 of the compounds in this reference contain C, listed by the fraction of their mass it makes up.
| Compound | Formula | Atoms | % by mass |
|---|---|---|---|
| diamond | C | 1 | 100.0% |
| graphite | C | 1 | 100.0% |
| pyrene | C16H10 | 16 | 95.0% |
| anthracene | C14H10 | 14 | 94.3% |
| phenanthrene | C14H10 | 14 | 94.3% |
| naphthalene | C10H8 | 10 | 93.7% |
| biphenyl | C12H10 | 12 | 93.5% |
| acetylene | C2H2 | 2 | 92.3% |
| styrene | C8H8 | 8 | 92.3% |
| benzene | C6H6 | 6 | 92.3% |
| toluene | C7H8 | 7 | 91.2% |
| ethylbenzene | C8H10 | 8 | 90.5% |
| cumene | C9H12 | 9 | 89.9% |
| mesitylene | C9H12 | 9 | 89.9% |
| beta-carotene | C40H56 | 40 | 89.5% |
| lycopene | C40H56 | 40 | 89.5% |
| isoprene | C5H8 | 5 | 88.2% |
| limonene | C10H16 | 10 | 88.2% |
| myrcene | C10H16 | 10 | 88.2% |
| pinene | C10H16 | 10 | 88.2% |
| squalene | C30H50 | 30 | 87.7% |
| carbazole | C12H9N | 12 | 86.2% |
| benzophenone | C13H10O | 13 | 85.7% |
| cycloheptane | C7H14 | 7 | 85.6% |
| cyclohexane | C6H12 | 6 | 85.6% |
Showing the 25 with the highest C content, of 383.
Calculate with carbon
- Molar mass of any formula containing it
- Electron configuration, including ions
- Effective nuclear charge by Slater's rules
- Average atomic mass from isotope abundances
Group 14
Atomic weights are the IUPAC 2021 standard values, abridged to the conventional five significant figures. Group, period, category and electron configuration are derived from the atomic number rather than stored, so they cannot drift out of step with it.