Symbol
Mo
Cr
Group Number
66
0
17
👆🏻
Period Number
54
2
7
👆🏻
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
74399877440473
7429905
54386242
👆🏻
Space Group Name
Im_ 3m
Im_ 3m
Space Group Number
229.00229.00
11
276
👆🏻
Interesting Facts
- Molybdenum is highly reactive metal, hence not found free in nature .
- Till 18th century Molybdenum element were often mistaken as a carbon or Lead.
- Chromium is highly reactive, hence it is not found free in nature.
- Ores of Chromites mineral are the major source of Chromium metal.
- Almost 90% leather tanning is done with the help of chromium.
Sources
Found in Minerals, Mining, Ores of Minerals
Found in Minerals, Mining, Ores of metals, Ores of Minerals
History
Who Discovered
Carl Wilhelm Scheele
Louis Nicolas Vauquelin
Discovery
In 1778
In Between 1797 - 1798
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %0.00 %
0
0.1
👆🏻
Abundance In Meteorites
0.00 %0.30 %
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.01 %
1E-37
8.1
👆🏻
Abundance In Oceans
0.00 %0.00 %
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- Its alloys are used to make engine parts, drills, saw blade, etc.
- Lubricant additive made up of Molybdenum disulfide is commonly used in the industry. It is also used as a catalyst.
- It is used to harden the steel and produces a stainless steel and other various alloys.
- It is also used to give proper finish to polished mirrors. Its chromium plates are used in bathroom fittings.
Industrial Uses
Aerospace Industry, Electrical Industry, Electronic Industry
Automobile Industry, Chemical Industry
Medical Uses
-
-
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Toxic
Highly Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.11 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.70 p.p.m.0.33 p.p.m.
0
170000
👆🏻
Melting Point
2,617.00 °C1,857.00 °C
-38.83
3410
👆🏻
Boiling Point
4,612.00 °C2,672.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Gray
Silver
Luster
Metallic
Metallic
Hardness
Mohs Hardness
5.508.50
0.2
8.5
👆🏻
Brinell Hardness
1,370.00 MPa687.00 MPa
0.14
3490
👆🏻
Vickers Hardness
1,400.00 MPa1,060.00 MPa
0
3920
👆🏻
Speed of Sound
5,400.00 m/s5,940.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
2.002.97
0.155
3.41
👆🏻
Reflectivity
58.00 %70.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Mo
Cr
Isotopes
Known Isotopes
2521
0
38
👆🏻
Electronegativity
Pauling Electronegativity
2.161.66
0
2.6
👆🏻
Sanderson Electronegativity
1.151.66
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.301.56
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
2.161.66
0.62
2.48
👆🏻
Allen Electronegativity
2.161.65
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
1.842.34
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
684.30 kJ/mol26,130.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,560.00 kJ/mol28,750.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,618.00 kJ/mol34,230.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
4,480.00 kJ/mol37,066.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,257.00 kJ/mol97,510.00 kJ/mol
392
97510
👆🏻
6th Energy Level
6,640.80 kJ/mol105,800.00 kJ/mol
1007
105800
👆🏻
7th Energy level
12,125.00 kJ/mol114,300.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
13,860.00 kJ/mol125,300.00 kJ/mol
730
125300
👆🏻
9th Energy Level
15,835.00 kJ/mol134,700.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
17,980.00 kJ/mol144,300.00 kJ/mol
392
144300
👆🏻
11th Energy Level
20,190.00 kJ/mol26,130.00 kJ/mol
392
169988
👆🏻
12th Energy Level
22,219.00 kJ/mol28,750.00 kJ/mol
0
189368
👆🏻
13th Energy Level
26,930.00 kJ/mol34,230.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
29,196.00 kJ/mol37,066.00 kJ/mol
380
86450
👆🏻
15th Energy Level
52,490.00 kJ/mol97,510.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
55,000.00 kJ/mol105,800.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
61,400.00 kJ/mol114,300.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
67,700.00 kJ/mol125,300.00 kJ/mol
0
134810
👆🏻
19th Energy Level
74,000.00 kJ/mol134,700.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
80,400.00 kJ/mol144,300.00 kJ/mol
0
171200
👆🏻
21st Energy Level
87,000.00 kJ/mol157,700.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
93,400.00 kJ/mol166,090.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
98,420.00 kJ/mol653.80 kJ/mol
357.6
198800
👆🏻
24th Energy Level
104,400.00 kJ/mol653.80 kJ/mol
297.3
195200
👆🏻
25th Energy Level
121,900.00 kJ/mol653.80 kJ/mol
0
121900
👆🏻
26th Energy Level
127,700.00 kJ/mol653.80 kJ/mol
357.6
127700
👆🏻
27th Energy Level
133,800.00 kJ/mol652.90 kJ/mol
0
133800
👆🏻
28th Energy Level
139,800.00 kJ/mol653.80 kJ/mol
297.3
139800
👆🏻
29th Energy Level
148,100.00 kJ/mol653.80 kJ/mol
0
148100
👆🏻
30th Energy Level
154,500.00 kJ/mol653.80 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
0.89 g/amp-hr0.32 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.60 eV4.50 eV
2.14
6
👆🏻
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Atomic Number
4224
3
117
👆🏻
Electron Configuration
[Kr] 4d5 5s1
[Ar] 3d5 4s1
Crystal Structure
Body Centered Cubic (BCC)
Body Centered Cubic (BCC)
Crystal Lattice
Atom
Number of Protons
4224
3
117
👆🏻
Number of Neutrons
5428
4
285
👆🏻
Number of Electrons
4224
3
117
👆🏻
Radius of an Atom
Atomic Radius
139.00 pm128.00 pm
0
348
👆🏻
Covalent Radius
154.00 pm139.00 pm
0
260
👆🏻
Van der Waals Radius
200.00 pm200.00 pm
0
348
👆🏻
Atomic Weight
95.95 amu52.00 amu
6.94
294
👆🏻
Atomic Volume
9.40 cm3/mol7.23 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
88.60 (-eV)170.00 (-eV)
0
392.42
👆🏻
Lattice Constant
314.70 pm291.00 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
1.031.86
0.423
1.9
👆🏻
Density
Density At Room Temperature
10.28 g/cm37.19 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
9.33 g/cm36.30 g/cm3
0.512
41
👆🏻
Tensile Strength
324.00 MPa689.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)774.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
126.00 GPa115.00 GPa
1.3
222
👆🏻
Bulk Modulus
230.00 GPa160.00 GPa
0
462
👆🏻
Young's Modulus
329.00 GPa279.00 GPa
0
528
👆🏻
Poisson Ratio
0.310.21
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile, Weldable
-
Magnetic Characteristics
Specific Gravity
10.227.19
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Antiferromagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
Semiconductor
-
Resistivity
53.40 nΩ·m125.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.19 106/cm Ω0.08 106/cm Ω
0
0.63
👆🏻
Electron Affinity
71.90 kJ/mol64.30 kJ/mol
0
222.8
👆🏻
Specific Heat
0.25 J/(kg K)0.45 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
24.06 J/mol·K23.35 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
138.00 W/m·K93.90 W/m·K
0
429
👆🏻
Critical Temperature
2,896.00 K1,907.00 K
26.3
3695
👆🏻
Thermal Expansion
4.80 µm/(m·K)4.90 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
594.10 kJ/mol348.80 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
27.61 kJ/mol15.31 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
653.00 kJ/mol397.50 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
28.70 J/mol.K23.80 J/mol.K
9.5
198.1
👆🏻