Periodic System for Chemists
Table
24
52.00

Cr

Chromium

Identification

CAS Number: 7440-47-3
Discovery Year: 1797
Discoverer: Louis Vauquelin
Discovery Location: France

Properties

Atomic Mass: 51.9961 →Density: 7.15 g/cm³ →
Crust Abundance: 102 mg/kg
Crystal Structure: BCC

Atomic Dimensions

Atomic Radius: 140 pm →
Atomic Radius (Rahm): 233 pm
Covalent Radius: 139 pm →
Van der Waals Radius: 206 pm
Metallic Radius: 119 pm
Atomic Volume: 7.23 cm³/mol
Lattice Constant: 2.88 Å

Thermodynamics

Melting Point: 2130 K →Boiling Point: 2945 K →Specific Heat: 0.488 J/(g·K) →Thermal Conductivity: 93.9 W/(m·K) →Heat of Fusion: 21 kJ/mol →Heat of Vaporization: 342 kJ/mol →
Heat of Formation: 397.48 kJ/mol

Electronic Structure

Electron Config: [Ar] 3d5 4s
Block: d
Period: 4 →Group: 6 →Electronegativity: 1.66 →Electron Affinity: 0.6659999999999999 eV →
Oxidation States: +2, +3, +6

Abundance & Geochemistry

Crust Abundance: 102 mg/kg
Sea Abundance: 0.0003 mg/L
Geochemical Class: first series transition metal
Goldschmidt Class: litophile

About

Hard silvery transition element. Used in decorative electroplating. Discovered in 1797 by Vauquelin.

Isotopes

Cr-52 52 83.79%
Cr-53 53 9.50%
Cr-50 50 4.35%
Cr-54 54 2.37%