Osmium Chromium Comparison
Periodic Table
Symbol
Os
Cr
Group Number
8
10
6
12
Period Number
6
4
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
7440042
99+
7440473
39
Space Group Name
P63/mmc
Im_ 3m
Space Group Number
194.00
5
229.00
1
Facts
Interesting Facts
- Osmium metal does not oxidize in air unless it is heated.
- But if it heated den it forms Osmium Tetroxide, which is highly toxic.
- 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 As a By-product, Found in Minerals, Mining
Found in Minerals, Mining, Ores of metals, Ores of Minerals
History
Who Discovered
Smithson Tennant
Louis Nicolas Vauquelin
Discovery
In 1803
In Between 1797 - 1798
Abundance
Abundance In Universe
3 * 10-7 %
21
1.5 * 10-3 %
7
Abundance In Sun
~0.0000002 %
25
~0.002 %
7
Abundance In Meteorites
0.00 %
28
0.30 %
7
Abundance In Earth's Crust
0.00 %
99+
0.01 %
13
Abundance In Oceans
Not Available
0.00 %
16
Abundance In Humans
Not Available
0.00 %
16
Uses
Uses & Benefits
- Its has very limited uses and its alloys are very hard and are used in the manufacturing of pen tips, pivots, needles and electrical contacts.
- It is also used as industrial catalyst to speed up the chemical reaction.
- 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, Automobile Industry, Electrical Industry, Electronic Industry
Automobile Industry, Chemical Industry
Medical Uses
NA
NA
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Highly Toxic
Highly Toxic
Present in Human Body
No
Yes
In Blood
Not Available
0.11 Blood/mg dm-3
12
In Bone
Not Available
0.33 p.p.m.
21
Physical Properties
Melting Point
3,045.00 °C
3
1,857.00 °C
14
Boiling Point
5,027.00 °C
6
2,672.00 °C
39
Appearance
Physical State
Solid
Solid
Color
Silvery Bluish-Gray
Silver
Luster
Metallic
Metallic
Hardness
Mohs Hardness
7.00
3
8.50
1
Brinell Hardness
3,490.00 MPa
1
687.00 MPa
16
Vickers Hardness
Not Available
1,060.00 MPa
10
Speed of Sound
4,940.00 m/s
11
5,940.00 m/s
5
Optical Properties
Allotropes
No
No
α Allotropes
Not Available
Not Available
β Allotropes
Not Available
Not Available
γ Allotropes
Not Available
Not Available
Chemical Properties
Chemical Formula
Os
Cr
Isotopes
Known Isotopes
35
4
21
18
Electronegativity
Pauling Electronegativity
2.20
4
1.66
18
Sanderson Electronegativity
Not Available
1.66
14
Allred Rochow Electronegativity
1.52
12
1.56
10
Allen Electronegativity
1.65
19
1.65
19
Electropositivity
Pauling Electropositivity
1.80
99+
2.34
36
Ionization Energies
1st Energy Level
840.00 kJ/mol
12
26,130.00 kJ/mol
1
2nd Energy Level
1,309.80 kJ/mol
99+
28,750.00 kJ/mol
1
3rd Energy Level
1,600.00 kJ/mol
99+
34,230.00 kJ/mol
1
4th Energy Level
Not Available
37,066.00 kJ/mol
1
5th Energy Level
Not Available
97,510.00 kJ/mol
1
6th Energy Level
Not Available
105,800.00 kJ/mol
1
7th Energy level
Not Available
114,300.00 kJ/mol
1
8th Energy Level
Not Available
125,300.00 kJ/mol
1
9th Energy Level
Not Available
134,700.00 kJ/mol
1
10th Energy Level
Not Available
144,300.00 kJ/mol
1
11th Energy Level
Not Available
26,130.00 kJ/mol
12
12th Energy Level
Not Available
28,750.00 kJ/mol
13
13th Energy Level
Not Available
34,230.00 kJ/mol
10
14th Energy Level
Not Available
37,066.00 kJ/mol
12
15th Energy Level
Not Available
97,510.00 kJ/mol
1
16th Energy Level
Not Available
105,800.00 kJ/mol
2
17th Energy Level
Not Available
114,300.00 kJ/mol
3
18th Energy Level
Not Available
125,300.00 kJ/mol
4
19th Energy Level
Not Available
134,700.00 kJ/mol
5
20th Energy Level
Not Available
144,300.00 kJ/mol
7
21st Energy Level
Not Available
157,700.00 kJ/mol
7
22nd Energy Level
Not Available
166,090.00 kJ/mol
6
Electrochemical Equivalent
1.77 g/amp-hr
38
0.32 g/amp-hr
99+
Electron Work Function
4.83 eV
8
4.50 eV
14
Other Chemical Properties
Chemical Stability, Ionization, Solubility
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
76
40
24
99+
Electron Configuration
[Xe] 4f14 5d6 6s2
[Ar] 3d5 4s1
Crystal Structure
Hexagonal Close Packed (HCP)
Body Centered Cubic (BCC)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
76
39
24
99+
Number of Neutrons
114
25
28
99+
Number of Electrons
76
39
24
99+
Radius of an Atom
Atomic Radius
133.80 pm
99+
128.00 pm
99+
Covalent Radius
Not Available
139.00 pm
99+
Van der Waals Radius
216.00 pm
24
200.00 pm
28
Atomic Weight
190.23 amu
35
52.00 amu
99+
Atomic Volume
8.49 cm3/mol
99+
7.23 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
91.40 (-eV)
12
170.00 (-eV)
4
Lattice Constant
273.44 pm
99+
291.00 pm
99+
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, π/2
Lattice C/A Ratio
1.58
14
Not Available
Mechanical Properties
Density
Density At Room Temperature
22.59 g/cm3
9
7.19 g/cm3
99+
Density When Liquid (at m.p.)
20.00 g/cm3
1
6.30 g/cm3
40
Tensile Strength
1,000.00 MPa
4
689.00 MPa
7
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
Not Available
0.00 (Pa)
24
Vapor Pressure at 2000 K
0.00 (Pa)
28
774.00 (Pa)
1
Elasticity properties
Shear Modulus
222.00 GPa
1
115.00 GPa
9
Bulk Modulus
462.00 GPa
1
160.00 GPa
11
Young's Modulus
Not Available
279.00 GPa
8
Poisson Ratio
0.25
24
0.21
32
Other Mechanical Properties
Ductile
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
22.57
2
7.19
99+
Magnetic Ordering
Paramagnetic
Antiferromagnetic
Electrical Properties
Electrical Property
Conductor
NA
Resistivity
81.20 nΩ·m
35
125.00 nΩ·m
27
Electrical Conductivity
0.11 106/cm Ω
18
0.08 106/cm Ω
25
Electron Affinity
106.10 kJ/mol
9
64.30 kJ/mol
15
Thermal Properties
Specific Heat
0.13 J/(kg K)
39
0.45 J/(kg K)
12
Molar Heat Capacity
24.70 J/mol·K
99+
23.35 J/mol·K
99+
Thermal Conductivity
87.60 W/m·K
19
93.90 W/m·K
17
Critical Temperature
Not Available
Not Available
Thermal Expansion
5.10 µm/(m·K)
99+
4.90 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
627.60 kJ/mol
7
348.80 kJ/mol
24
Enthalpy of Fusion
29.30 kJ/mol
4
15.31 kJ/mol
20
Enthalpy of Atomization
669.00 kJ/mol
6
397.50 kJ/mol
21
Standard Molar Entropy
32.60 J/mol.K
99+
23.80 J/mol.K
99+
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