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Mo Molybdenum
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

42
Mo
Molybdenum
Element 42 of Periodic table is Molybdenum with atomic number 42, atomic weight 95.94. Molybdenum, symbol Mo, has a Body Centered Cubic structure and Gray color. Molybdenum is a Transition Metal element. It is part of group 6 (chromium family). Know everything about Molybdenum Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
42 Mo - Molybdenum | SchoolMyKids

Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin molybdaenum, from Ancient Greek Μόλυβδος molybdos, meaning lead, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele.

It belongs to group 6 of the periodic table having trivial name .

Molybdenum Facts

Read key information and facts about element Molybdenum

NameMolybdenum
Atomic Number42
Atomic SymbolMo
Atomic Weight95.94
PhaseSolid
ColorGray
Appearancegray metallic
ClassificationTransition Metal
Group in Periodic Table6
Group Namechromium family
Period in Periodic Tableperiod 5
Block in Periodic Tabled -block
Electronic Configuration[Kr] 4d5 5s1
Electronic Shell Structure (Electrons per shell)2, 8, 18, 13, 1
Melting Point2896 K
Boiling Point4912 K
CAS NumberCAS7439-98-7
123456789101112131415161718
1
1
H
Hydrogen
1.008

Atomic #

Electronic Shell #

Symbol
Name
Atomic Weight
HGas
HgLiquid
CSolid
Metals
Metalloids
NonMetals
Alkali metals
Alkali earth metals
Lanthanoids
Transition metals
Post-transition metals
Other nonmetals
Halogens
Nobel gas
Actinoids
2
He
Helium
4.003
2
3
Li
Lithium
6.941
4
Be
Beryllium
9.012
5
B
Boron
10.811
6
C
Carbon
12.011
7
N
Nitrogen
14.007
8
O
Oxygen
15.999
9
F
Fluorine
18.998
10
Ne
Neon
20.180
3
11
Na
Sodium
22.990
12
Mg
Magnesium
24.305
13
Al
Aluminium
26.982
14
Si
Silicon
28.085
15
P
Phosphorus
30.974
16
S
Sulfur
32.065
17
Cl
Chlorine
35.453
18
Ar
Argon
39.948
4
19
K
Potassium
39.098
20
Ca
Calcium
40.078
21
Sc
Scandium
44.956
22
Ti
Titanium
47.867
23
V
Vanadium
50.941
24
Cr
Chromium
51.996
25
Mn
Manganese
54.938
26
Fe
Iron
55.845
27
Co
Cobalt
58.933
28
Ni
Nickel
58.693
29
Cu
Copper
63.546
30
Zn
Zinc
65.409
31
Ga
Gallium
69.723
32
Ge
Germanium
72.640
33
As
Arsenic
74.922
34
Se
Selenium
78.960
35
Br
Bromine
79.904
36
Kr
Krypton
83.798
5
37
Rb
Rubidium
85.468
38
Sr
Strontium
87.620
39
Y
Yttrium
88.906
40
Zr
Zirconium
91.224
41
Nb
Niobium
92.906
42
Mo
Molybdenum
95.940
43
Tc
Technetium
98
44
Ru
Ruthenium
101.070
45
Rh
Rhodium
102.906
46
Pd
Palladium
106.420
47
Ag
Silver
107.868
48
Cd
Cadmium
112.411
49
In
Indium
114.818
50
Sn
Tin
118.710
51
Sb
Antimony
121.760
52
Te
Tellurium
127.600
53
I
Iodine
126.904
54
Xe
Xenon
131.293
6
55
Cs
Cesium
132.905
56
Ba
Barium
137.327
57 - 71
La - Lu
Lanthanides
72
Hf
Hafnium
178.490
73
Ta
Tantalum
180.948
74
W
Tungsten
183.840
75
Re
Rhenium
186.207
76
Os
Osmium
190.230
77
Ir
Iridium
192.217
78
Pt
Platinum
195.078
79
Au
Gold
196.967
80
Hg
Mercury
200.590
81
Tl
Thallium
204.383
82
Pb
Lead
207.200
83
Bi
Bismuth
208.980
84
Po
Polonium
209
85
At
Astatine
210
86
Rn
Radon
222
7
87
Fr
Francium
223
88
Ra
Radium
226
89 - 103
Ac - Lr
Actinides
104
Rf
Rutherfordium
261
105
Db
Dubnium
262
106
Sg
Seaborgium
266
107
Bh
Bohrium
264
108
Hs
Hassium
277
109
Mt
Meitnerium
268
110
Ds
Darmstadtium
281
111
Rg
Roentgenium
272
112
Cn
Copernicium
285
113
Nh
Nihonium
284
114
Fl
Flerovium
289
115
Mc
Moscovium
288
116
Lv
Livermorium
292
117
Ts
Tennessine
294
118
Og
Oganesson
294
Lanthanides
57
La
Lanthanum
138.905
58
Ce
Cerium
140.116
59
Pr
Praseodymium
140.908
60
Nd
Neodymium
144.240
61
Pm
Promethium
145
62
Sm
Samarium
150.360
63
Eu
Europium
151.964
64
Gd
Gadolinium
157.250
65
Tb
Terbium
158.925
66
Dy
Dysprosium
162.500
67
Ho
Holmium
164.930
68
Er
Erbium
167.259
69
Tm
Thulium
168.934
70
Yb
Ytterbium
173.040
71
Lu
Lutetium
174.967
Actinides
89
Ac
Actinium
227
90
Th
Thorium
232.038
91
Pa
Protactinium
231.036
92
U
Uranium
238.029
93
Np
Neptunium
237
94
Pu
Plutonium
244
95
Am
Americium
243
96
Cm
Curium
247
97
Bk
Berkelium
247
98
Cf
Californium
251
99
Es
Einsteinium
252
100
Fm
Fermium
257
101
Md
Mendelevium
258
102
No
Nobelium
259
103
Lr
Lawrencium
262

How to Locate Molybdenum on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 42 to find Molybdenum on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Molybdenum on periodic table look for cross section of group 6 and period 5 in the modern periodic table.

Molybdenum History

The element Molybdenum was discovered by W. Scheele in year 1778 in Sweden. Molybdenum was first isolated by J. Hjelm in 1781. Molybdenum derived its name from the Greek word molybdos meaning 'lead'.

Scheele recognised the metal as a constituent ofmolybdena.

Molybdenum Presence: Abundance in Nature and Around Us

The table below shows the abundance of Molybdenum in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

 ppb by weight (1ppb =10^-7 %)ppb by atoms (1ppb =10^-7 %)
Abundance in Universe50.1
Abundance in Sun90.1
Abundance in Meteorites1200250
Abundance in Earth's Crust1100230
Abundance in Oceans100.64
Abundance in Humans1007

Crystal Structure of Molybdenum

The solid state structure of Molybdenum is Body Centered Cubic.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

abc
314.7 pm314.7 pm314.7 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alphabetagamma
π/2 π/2 π/2

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group NameIm_ 3m 42 Mo Molybdenum - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number229
Crystal StructureBody Centered Cubic

Molybdenum Atomic and Orbital Properties

Molybdenum atoms have 42 electrons and the electronic shell structure is [2, 8, 18, 13, 1] with Atomic Term Symbol (Quantum Numbers) 7S3.

Atomic Number42
Number of Electrons (with no charge)42
Number of Protons42
Mass Number96
Number of Neutrons54
Shell structure (Electrons per energy level)2, 8, 18, 13, 1
Electron Configuration[Kr] 4d5 5s1
Valence Electrons4d5 5s1
Valence (Valency)6
Main Oxidation States4, 6
Oxidation States-4, -2, -1, 0, 1, 2, 3, 4, 5, 6
Atomic Term Symbol (Quantum Numbers)7S3

Bohr Atomic Model of Molybdenum - Electrons per energy level

42 Mo Molybdenum - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Molybdenum - neutral Molybdenum atom

Abbreviated electronic configuration of Molybdenum

The ground state abbreviated electronic configuration of Neutral Molybdenum atom is [Kr] 4d5 5s1. The portion of Molybdenum configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Kr]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 4d5 5s1, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Molybdenum

Complete ground state electronic configuration for the Molybdenum atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d5 5s1

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

  • As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
  • The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
  • Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
  • Electron configuration of Molybdenum
    Atomic Structure of Molybdenum

    Molybdenum atomic radius is 190 pm, while it's covalent radius is 145 pm.

    Atomic Radius Calculated

    190 pm (1.9 Å)

    Atomic Radius Empirical

    145 pm (1.45 Å)

    Atomic Volume9.333 cm3/mol
    Covalent Radius145 pm (1.45 Å)
    Van der Waals Radius-
    Neutron Cross Section2.6
    Neutron Mass Absorption 0.0009

    Atomic Spectrum of Molybdenum

    Atomic Spectrum of Molybdenum | SchoolMyKids

    Molybdenum Chemical Properties: Molybdenum Ionization Energies and electron affinity

    The electron affinity of Molybdenum is 71.9 kJ/mol.

    Valence6
    Electronegativity2.16
    ElectronAffinity71.9 kJ/mol

    Ionization Energy of Molybdenum

    Refer to table below for Ionization energies of Molybdenum

    Ionization energy numberEnthalpy - kJ/mol
    1st684.3
    2nd1560
    3rd2618
    4th4480
    5th5257
    6th6640.8
    7th12125
    8th13860
    9th15835
    10th17980
    11th20190
    12th22219
    13th26930
    14th29196
    15th52490
    16th55000
    17th61400
    18th67700
    19th74000
    20th80400
    21st87000
    22nd93400
    23rd98420
    24th104400
    25th121900
    26th127700
    27th133800
    28th139800
    29th148100
    30th154500

    Molybdenum Physical Properties

    Refer to below table for Molybdenum Physical Properties

    Density10.28 g/cm3(when liquid at m.p density is $9.33 g/cm3)
    Molar Volume9.333 cm3/mol

    Elastic Properties

    Young Modulus329
    Shear Modulus20 GPa
    Bulk Modulus 230 GPa
    Poisson Ratio0.31

    Hardness of Molybdenum - Tests to Measure of Hardness of Element

    Mohs Hardness5.5 MPa
    Vickers Hardness1530 MPa
    Brinell Hardness1500 MPa

    Molybdenum Electrical Properties

    Molybdenum is Conductor of electricity. Refer to table below for the Electrical properties ofMolybdenum

    Electrical Conductivity20000000 S/m
    Resistivity5e-8 m Ω
    Superconducting Point0.915

    Molybdenum Heat and Conduction Properties

    Thermal Conductivity139 W/(m K)
    Thermal Expansion0.0000048 /K

    Molybdenum Magnetic Properties

    Magnetic TypeParamagnetic
    Curie Point-
    Mass Magnetic Susceptibility1.17e-8 m3/kg
    Molar Magnetic Susceptibility1.122e-9 m3/mol
    Volume Magnetic Susceptibility0.0001203

    Optical Properties of Molybdenum

    Refractive Index-

    Acoustic Properties of Molybdenum

    Speed of Sound6190 m/s

    Molybdenum Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Molybdenum

    Melting Point2896 K (2622.85°C, 4753.129999999999 °F)
    Boiling Point4912 K (4638.85°C, 8381.93 °F)
    Critical Temperature-
    Superconducting Point0.915

    Enthalpies of Molybdenum

    Heat of Fusion36 kJ/mol
    Heat of Vaporization600 kJ/mol
    Heat of Combustion-

    Molybdenum Isotopes - Nuclear Properties of Molybdenum

    Molybdenum has 33 isotopes, with between 83 and 115 nucleons. Molybdenum has 6 stable naturally occuring isotopes.

    Isotopes of Molybdenum - Naturally occurring stable Isotopes: 92Mo, 94Mo, 95Mo, 96Mo, 97Mo, 98Mo.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    83Mo424183Synthetic
    84Mo424284Synthetic
    85Mo424385Synthetic
    86Mo424486Synthetic
    87Mo424587Synthetic
    88Mo424688Synthetic
    89Mo424789Synthetic
    90Mo424890Synthetic
    91Mo424991Synthetic
    92Mo42509214.84%StableN/A
    93Mo425193Synthetic
    94Mo4252949.25%StableN/A
    95Mo42539515.92%StableN/A
    96Mo42549616.68%Stable
    97Mo4255979.55%StableN/A
    98Mo42569824.13%StableN/A
    99Mo425799Synthetic
    100Mo42581009.63%StableN/A
    101Mo4259101Synthetic
    102Mo4260102Synthetic
    103Mo4261103Synthetic
    104Mo4262104Synthetic
    105Mo4263105Synthetic
    106Mo4264106Synthetic
    107Mo4265107Synthetic
    108Mo4266108Synthetic
    109Mo4267109Synthetic
    110Mo4268110Synthetic
    111Mo4269111Synthetic
    112Mo4270112Synthetic
    113Mo4271113Synthetic
    114Mo4272114Synthetic
    115Mo4273115Synthetic

    Regulatory and Health - Health and Safety Parameters and Guidelines

    Database Search

    List of unique identifiers to search the element in various chemical registry databases

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS7439-98-7
    RTECS NumberRTECSQA4680000
    CID Number CID23932
    Gmelin Number-
    NSC Number-