Molybdenum

42
Mo
Group
6
Period
5
Block
d
Protons
Electrons
Neutrons
42
42
54
General Properties
Atomic Number
42
Atomic Weight
95.96
Mass Number
96
Category
Transition metals
Color
Gray
Radioactive
No
From the Greek word molybdo, lead
Crystal Structure
Body Centered Cubic
History
Molybdenite was often confused for graphite and it was thought to contain lead.

In 1778 Swedish scientist Carl Wilhelm Scheele proved that molybdenite was not graphite nor did it contain lead.

In 1781, Scheele's friend and countryman, Peter J. Hjelm isolated the metal by using carbon and linseed oil.
Electrons per shell
2, 8, 18, 13, 1
Electron Configuration
[Kr] 4d5 5s1
Mo
Molybdenum is essential for plant foliage health
Physical Properties
Phase
Solid
Density
10.22 g/cm3
Melting Point
2896.15 K | 2623 °C | 4753.4 °F
Boiling Point
4912.15 K | 4639 °C | 8382.2 °F
Heat of Fusion
36 kJ/mol
Heat of Vaporization
600 kJ/mol
Specific Heat Capacity
0.251 J/g·K
Abundance in Earth's crust
0.00011%
Abundance in Universe
5×10-7%
Molybdenum
Image Credits: Images-of-elements
Molybdenum with rough, oxidized surface
CAS Number
7439-98-7
PubChem CID Number
23932
Atomic Properties
Atomic Radius
139 pm
Covalent Radius
154 pm
Electronegativity
2.16 (Pauling scale)
Ionization Potential
7.0924 eV
Atomic Volume
9.4 cm3/mol
Thermal Conductivity
1.38 W/cm·K
Oxidation States
-2, -1, 1, 2, 3, 4, 5, 6
Applications
Molybdenum is used as glass furnace electrodes due to its high melting point.

The metal is also used in nuclear energy applications and for missile and aircraft parts.

Molybdenum is valuable as a catalyst in the refining of petroleum.

Molybdenum is used in small quantities to harden steel and is used in many alloys.
Molybdenum is toxic in all but small quantities
Isotopes
Stable Isotopes
92Mo, 94Mo, 95Mo, 96Mo, 97Mo, 98Mo
Unstable Isotopes
83Mo, 84Mo, 85Mo, 86Mo, 87Mo, 88Mo, 89Mo, 90Mo, 91Mo, 93Mo, 99Mo, 100Mo, 101Mo, 102Mo, 103Mo, 104Mo, 105Mo, 106Mo, 107Mo, 108Mo, 109Mo, 110Mo, 111Mo, 112Mo, 113Mo, 114Mo, 115Mo