molybdenum

• Description
• General information
• Physical data
• Radii
• Electronegativities
• Solid state structure
• Temperatures
• Enthalpies
• Ionization Enthalpies
• Isotopes
• Further information

Description

Molybdenum is a silvery-white, hard, transition metal. Scheele discovered it in 1778. It was often confused with graphite and lead ore. Molybdenum is used in alloys, electrodes and catalysts. The World War 2 German artillery piece called "Big Bertha" contains molybdenum as an essential component of its steel.

General information

Discoveror: Carl William Scheele
Date discovered: 1781
Discovered at: Sweden
Meaning of name: From the Greek word "molybdos" meaning "lead"

Physical data

Standard state: solid at 298 K
Colour: grey metallic
Density of solid at ambient temperature/kg m^-3: 10280
Molar volume/cm³: 9.38

Radii /pm

Atomic: 190
Covalent (single bond):
Pauling radius for the ion [Mo]^-: no data

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	175.3	no data	72.9	no data

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 2.2
Allred Rochow: 1.30

Crystal Structure

structure: bcc (body-centred cubic)

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.

Temperatures (/K)

melting point: 2896
boiling point: 4912

Enthalpies /kJ mol^-1

fusion: 36.0
vaporization: 603

single bond enthalpies:

Mo-F	Mo-Cl	Mo-Br	Mo-I	Mo-Mo
no data	no data	no data	no data	406

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	685.0
2nd	1558
3rd	2621
4th	4480
5th	5900
6th	6560
7th	12230
8th	14800

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
92Mo	91.906809 (4)	14.84 (4)
94Mo	93.9050853 (26)	9.25 (3)
95Mo	94.9058411 (22)	15.92 (5)
96Mo	95.9046785 (22)	16.68 (5)
97Mo	96.9060205 (22)	9.55 (3)
98Mo	97.9054073 (22)	24.13 (7)
100Mo	99.907477 (6)	9.63 (3)

Further Information

• Additional information about WebElements 1.2.2
• This is a licensed copy (here is the full list) of WebElements 1.2.2 and contains a subset of the material contained within the main version of WebElements (version 2)
• For further information please try WebElements version 2
• Sheffield Chemdex: perhaps the largest internet chemistry directory
• Sheffield Chemputer: interactive chemistry calculators on the WWW