Periodic System for Chemists
Table
17
35.45

Cl

Chlorine

Identification

CAS Number: 7782-50-5
Discovery Year: 1774
Discoverer: Carl Wilhelm Scheele
Discovery Location: Sweden

Properties

Atomic Mass: 35.45 →Density: 0.002898 g/cm³ →
Crust Abundance: 145 mg/kg
Crystal Structure: ORC

Atomic Dimensions

Atomic Radius: 100 pm →
Atomic Radius (Rahm): 206 pm
Covalent Radius: 102 pm →
Van der Waals Radius: 175 pm
Atomic Volume: 18.7 cm³/mol
Lattice Constant: 6.24 Å

Thermodynamics

Melting Point: 172.2 K →Boiling Point: 238.6 K →Thermal Conductivity: 0.009 W/(m·K) →Heat of Fusion: 6.41 kJ/mol →Heat of Vaporization: 20.41 kJ/mol →
Heat of Formation: 121.302 kJ/mol

Electronic Structure

Electron Config: [Ne] 3s2 3p5
Block: p
Period: 3 →Group: 17 →Electronegativity: 3.16 →Electron Affinity: 3.612725 eV →
Oxidation States: -1, +1, +3, +5, +7

Abundance & Geochemistry

Crust Abundance: 145 mg/kg
Sea Abundance: 19400 mg/L
Geochemical Class: semi-volatile
Goldschmidt Class: litophile

About

Chlorine is a yellow-green gas with a pungent odor. It is used for water purification, bleaching, and in the production of many chemicals.

Isotopes

Cl-35 35 75.50%
Cl-37 37 23.90%