41
Nb
Niobium
92.906372
2818121
#41

Niobium

transition metal· Solid·92.906372 u

Niobium, formerly columbium, is a chemical element with symbol Nb (formerly Cb) and atomic number 41. It is a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite. The name comes from Greek mythology:Niobe, daughter of Tantalus since it is so similar to tantalum.

Identity

Symbol
Nb
Atomic Number
41
Atomic Mass
92.906372 u
Category
transition metal
Block
d-block
Period
5
Group
5
Appearance
gray metallic, bluish when oxidized
Year Discovered
1801 CE
Discovered By
Charles Hatchett
Named By
Niobe

Electrons

Configuration
[Kr] 4d4 5s1
Full Configuration
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1 4d4
Shells
2, 8, 18, 12, 1
Electronegativity
1.6
Electron Affinity
88.516
Oxidation States
+5, +3
Ionization Energies
652.1, 1380, 2416, 3700, 4877 … +2 more

Physical Properties

Niobium
State at
Solid
Melting Point
2750
Boiling Point
5017
Density
8.57
Molar Heat
24.6 J/(mol·K)
Crystal Structure
BCC
Magnetic Ordering
Paramagnetic

Mechanical

Atomic Radius
198 pm
Covalent Radius
164 pm
Van der Waals
207 pm
Metallic Radius
146 pm
Mohs Hardness
6
Brinell Hardness
736 MPa MPa
Vickers Hardness
1320 MPa MPa
Bulk Modulus
170 GPa GPa
Shear Modulus
38 GPa GPa
Young's Modulus
105 GPa GPa

Thermal & Electrical

Thermal Conductivity
53.7 W/(m K) W/(m·K)
Electrical Conductivity
6.93 MS/m S/m
Specific Heat
265 J/(kg K) J/(g·K)
Heat of Vaporization
690 kJ/mol kJ/mol
Heat of Fusion
30 kJ/mol kJ/mol

Abundance

Universe
2.00 ppb
Sun
4.00 ppb
Meteorite
280 ppb
Earth's Crust
20 ppm
Ocean
10.0 ppt
Human Body
0