Chlorine (Cl)
Chlorum
Chlorine (Cl) is a halogen in period 3, group 17. Its relative atomic mass is 35.45 and the molar mass of the atom is 35.45 g/mol; the molar mass of Cl₂ is 70.9 g/mol.
Atomic number 17
Atomic mass 35.45
Molar mass 35.45 g/mol Cl₂: 70.9 g/mol
Category Halogen Gas
Properties of chlorine
| Atomic number | 17 |
|---|---|
| Symbol | Cl |
| Latin name | Chlorum |
| Relative atomic mass | 35.45 |
| Molar mass | 35.45 g/mol · Cl₂: 70.9 g/mol |
| Group, period, block | 17, 3, p |
| Category | Halogen |
| State at 20 °C | Gas |
| Electron configuration | [Ne] 3s² 3p⁵ |
| Electronegativity (Pauling) | 3.16 |
| Atomic radius | 100 pm |
Electron configuration of chlorine
Electrons per shell
K2L8M7
Full notation
1s² 2s² 2p⁶ 3s² 3p⁵
Noble-gas notation
17 protons · 17 electrons[Ne] 3s² 3p⁵
Formula and compounds of chlorine
Simple substanceCl₂chlorineMolar mass of Cl₂: 70.9 g/mol
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Frequently asked questions
The relative atomic mass of chlorine is 35.45, so the molar mass of the atom is 35.45 g/mol; the molar mass of Cl₂ is 70.9 g/mol.
Full: 1s² 2s² 2p⁶ 3s² 3p⁵. Noble-gas notation: [Ne] 3s² 3p⁵.