Nb

Niobium

Identification

CAS Number: 7440-03-1

Discovery Year: 1801

Discoverer: Charles Hatchet

Discovery Location: England

Properties

Atomic Mass: 92.90637 →Density: 8.57 g/cm³ →

Crust Abundance: 20 mg/kg

Crystal Structure: BCC

Atomic Dimensions

Atomic Radius: 145 pm →

Atomic Radius (Rahm): 250.99999999999997 pm

Covalent Radius: 164 pm →

Van der Waals Radius: 218.00000000000003 pm

Metallic Radius: 134 pm

Atomic Volume: 10.8 cm³/mol

Lattice Constant: 3.3 Å

Thermodynamics

Melting Point: 2741 K →Boiling Point: 5015 K →Specific Heat: 0.268 J/(g·K) →Thermal Conductivity: 53.7 W/(m·K) →Heat of Fusion: 26.8 kJ/mol →Heat of Vaporization: 680 kJ/mol →

Heat of Formation: 733 kJ/mol

Electronic Structure

Electron Config: [Kr] 4d4 5s

Block: d

Period: 5 →Group: 5 →Electronegativity: 1.6 →Electron Affinity: 0.917406 eV →

Oxidation States: +3, +5

Abundance & Geochemistry

Crust Abundance: 20 mg/kg

Sea Abundance: 0.00001 mg/L

Geochemical Class: high field strength

Goldschmidt Class: litophile

About

Soft, ductile grey-blue metallic transition element. Used in special steels and in welded joints to increase strength. Combines with halogens and oxidizes in air at 200 degrees celsius. Discovered by Charles Hatchett in 1801 and isolated by Blomstrand in 1864. Called Columbium originally.

Isotopes

Nb-93 93 100.00%