Carbon (C)
Carbon is the 6th element, a reactive nonmetal in the p-block. Its standard atomic weight is 12.011.
Carbon
12.011
What the table records
- Atomic number
- 6
- Standard atomic weight
- 12.011
- Group
- 14
- Period
- 2
- Block
- p-block
- Category
- Reactive nonmetal
- [He] 2s2 2p2
- Valence electrons
- 4
- Typical valence
- 4
- Van der Waals radius
- 1.7 Å
- Covalent radius
- 0.76 Å
Molecules containing carbon
The lightest named structures in this library that contain C.
Carbon
C · 12.01 g/mol
Carbon(1-) monohydride
CH- · 13.02 g/mol
Methyl
CH₃ · 15.04 g/mol
Methane
CH₄ · 16.04 g/mol
Cyanide
CN- · 26.02 g/mol
Acetylene
C₂H₂ · 26.04 g/mol
Hydrogen Cyanide
CHN · 27.03 g/mol
Carbon Monoxide
CO · 28.01 g/mol
Ethylene
C₂H₄ · 28.05 g/mol
Ethyl
C₂H₅ · 29.06 g/mol
Formaldehyde
CH₂O · 30.03 g/mol
Methylamide
CH₄N- · 30.05 g/mol
How to read these numbers
The standard atomic weight is an average over the isotopes as they occur naturally, which is why it is rarely a whole number. It is the figure a molar mass calculation uses. Work in mass spectrometry wants the monoisotopic mass of a single isotope instead, which is a different number.
The two radii are not the same measurement. The covalent radius is half the distance between two bonded atoms of the element; the van der Waals radius is how close a non-bonded atom gets before repulsion takes over, and is always the larger. Space-filling models are drawn with the second, ball-and-stick models with the first — which is why the same molecule looks so different in the two.