Periodic System for Chemists
Table
26
55.84

Fe

Iron

Identification

CAS Number: 7439-89-6
Discoverer: Known to the ancients.

Properties

Atomic Mass: 55.845 →Density: 7.87 g/cm³ →
Crust Abundance: 56300 mg/kg
Crystal Structure: BCC

Atomic Dimensions

Atomic Radius: 140 pm →
Atomic Radius (Rahm): 237 pm
Covalent Radius: 142 pm →
Van der Waals Radius: 204 pm
Metallic Radius: 117 pm
Atomic Volume: 7.1 cm³/mol
Lattice Constant: 2.87 Å

Thermodynamics

Melting Point: 1808 K →Boiling Point: 3023 K →Specific Heat: 0.443 J/(g·K) →Thermal Conductivity: 80.4 W/(m·K) →Heat of Fusion: 13.8 kJ/mol →Heat of Vaporization: 340 kJ/mol →
Heat of Formation: 415.5 kJ/mol

Electronic Structure

Electron Config: [Ar] 3d6 4s2
Block: d
Period: 4 →Group: 8 →Electronegativity: 1.83 →Electron Affinity: 0.151 eV →
Oxidation States: +2, +3

Abundance & Geochemistry

Crust Abundance: 56300 mg/kg
Sea Abundance: 0.002 mg/L
Geochemical Class: major
Goldschmidt Class: siderophile

About

Iron is a metal that has been used by humans for thousands of years. It is the main component of steel and is essential for blood hemoglobin.

Isotopes

Fe-56 56 91.75%
Fe-54 54 5.85%
Fe-57 57 2.12%
Fe-58 58 0.2820%