17Gas
Cl 35.453 Atomic mass · uHalogens
Chlorine
Chlorine is a chemical element with symbol Cl and atomic number 17. It also has a relative atomic mass of 35.5. Chlorine is in the halogen group (17) and is the second lightest halogen following fluorine.
Discovery 1774 (Carl Wilhelm Scheele)
K2L8M7
Physical properties
Values for the element in its standard state.
- Density
- 0.003214g/cm³
- Melting point
- 172K
- Boiling point
- 239K
- Atomic radius
- 99pm
- Bonding type
- Covalent network
- Molar heat
- Not available
Inside the atom
Electron arrangement and the energy behind its behavior.
Full electron configuration
1s, 2 electrons; 2s, 2 electrons; 2p, 6 electrons; 3s, 2 electrons; 3p, 5 electrons;
[Ne] represents 10 core electrons. The full view shows them explicitly.
17 electrons Orbital order preserved from source
- Electronegativity
- 3.16Pauling scale
- First ionization energy
- 1,251kJ/mol
- Electron affinity
- 349kJ/mol
- Van der Waals radius
- 175pm
Cl ChlorineAtomic number 17
1,251kJ/mol
Atomic numberGaps indicate unavailable data
About chlorine
- Appearance
- Pale yellow-green gas
- Discovery
- 1774 (Carl Wilhelm Scheele)
- Data source
- Read the reference
A missing value means it is unavailable in this reference dataset. Values can vary with measurement method and conditions.