Chromium vs Mercury
Periodic Table
Symbol
Cr
Hg
Group Number
6
12
12
6
Period Number
4
6
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
7440473
39
7439976
99+
Space Group Name
Im_ 3m
R_ 3m
Space Group Number
229.00
1
166.00
6
Facts
Interesting Facts
- 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.
- At room temperature mercury is found in a liquid state.
- A coin of pound or rupees floats in mercury.
- Because of its low melting point and boiling point it is used in thermometers.
Sources
Found in Minerals, Mining, Ores of metals, Ores of Minerals
Mining, Ores of Minerals
History
Who Discovered
Louis Nicolas Vauquelin
Ancient Chinese and Indians
Discovery
In Between 1797 - 1798
Before 2000 BCE
Abundance
Abundance In Universe
1.5 * 10-3 %
7
Not Available
Abundance In Sun
~0.002 %
7
~-9999 %
Abundance In Meteorites
0.30 %
7
Not Available
Abundance In Earth's Crust
0.01 %
13
0.05 %
9
Abundance In Oceans
0.00 %
16
Not Available
Abundance In Humans
0.00 %
16
Not Available
Uses
Uses & Benefits
- 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.
- It is a liquid metal at room temperature, but it is a toxic heavy metal and hence many uses of mercury are under review or phased out.
- It is manly used as a catalysts in chemical industry.
Industrial Uses
Automobile Industry, Chemical Industry
Electrical Industry, Electronic Industry
Medical Uses
NA
Dentistry
Other Uses
Alloys
Alloys, Mirror Manufacturing, Pharmaceutical Industry
Biological Properties
Toxicity
Highly Toxic
Highly Toxic
Present in Human Body
Yes
Yes
In Blood
0.11 Blood/mg dm-3
12
0.01 Blood/mg dm-3
23
In Bone
0.33 p.p.m.
21
0.45 p.p.m.
19
Physical Properties
Melting Point
1,857.00 °C
14
Not Available
Boiling Point
2,672.00 °C
39
356.58 °C
99+
Appearance
Physical State
Solid
Liquid
Color
Silver
Silver
Luster
Metallic
NA
Hardness
Mohs Hardness
8.50
1
Not Available
Brinell Hardness
687.00 MPa
16
Not Available
Vickers Hardness
1,060.00 MPa
10
Not Available
Speed of Sound
5,940.00 m/s
5
1,451.40 m/s
99+
Optical Properties
Refractive Index
Not Available
1.00
3
Reflectivity
Not Available
73.00 %
8
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
Cr
Hg
Isotopes
Known Isotopes
21
18
34
5
Electronegativity
Pauling Electronegativity
1.66
18
2.00
7
Sanderson Electronegativity
1.66
14
2.20
7
Allred Rochow Electronegativity
1.56
10
1.44
17
Mulliken-Jaffe Electronegativity
Not Available
1.81
9
Allen Electronegativity
1.65
19
1.44
30
Electropositivity
Pauling Electropositivity
2.34
36
2.00
99+
Ionization Energies
1st Energy Level
26,130.00 kJ/mol
1
1,007.10 kJ/mol
4
2nd Energy Level
28,750.00 kJ/mol
1
1,810.00 kJ/mol
20
3rd Energy Level
34,230.00 kJ/mol
1
3,300.00 kJ/mol
20
4th Energy Level
37,066.00 kJ/mol
1
Not Available
5th Energy Level
97,510.00 kJ/mol
1
Not Available
6th Energy Level
105,800.00 kJ/mol
1
Not Available
7th Energy level
114,300.00 kJ/mol
1
Not Available
8th Energy Level
125,300.00 kJ/mol
1
Not Available
9th Energy Level
134,700.00 kJ/mol
1
Not Available
10th Energy Level
144,300.00 kJ/mol
1
Not Available
11th Energy Level
26,130.00 kJ/mol
12
Not Available
12th Energy Level
28,750.00 kJ/mol
13
Not Available
13th Energy Level
34,230.00 kJ/mol
10
Not Available
14th Energy Level
37,066.00 kJ/mol
12
Not Available
15th Energy Level
97,510.00 kJ/mol
1
Not Available
16th Energy Level
105,800.00 kJ/mol
2
Not Available
17th Energy Level
114,300.00 kJ/mol
3
Not Available
18th Energy Level
125,300.00 kJ/mol
4
Not Available
19th Energy Level
134,700.00 kJ/mol
5
Not Available
20th Energy Level
144,300.00 kJ/mol
7
Not Available
21st Energy Level
157,700.00 kJ/mol
7
Not Available
22nd Energy Level
166,090.00 kJ/mol
6
Not Available
Electrochemical Equivalent
0.32 g/amp-hr
99+
3.74 g/amp-hr
10
Electron Work Function
4.50 eV
14
4.49 eV
15
Other Chemical Properties
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Flammability, Ionization, Solubility
Atomic Properties
Atomic Number
24
99+
80
36
Electron Configuration
[Ar] 3d5 4s1
[Xe] 4f14 5d10 6s2
Crystal Structure
Body Centered Cubic (BCC)
Rhombohedral (RHO)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
RHO-Crystal-Structure-of-Mercury.jpg#100
Atom
Number of Protons
24
99+
80
36
Number of Neutrons
28
99+
121
22
Number of Electrons
24
99+
80
36
Radius of an Atom
Atomic Radius
128.00 pm
99+
151.00 pm
32
Covalent Radius
139.00 pm
99+
132.00 pm
99+
Van der Waals Radius
200.00 pm
28
155.00 pm
99+
Atomic Weight
52.00 amu
99+
200.59 amu
32
Atomic Volume
7.23 cm3/mol
99+
14.82 cm3/mol
35
Adjacent Atomic Numbers
Valence Electron Potential
170.00 (-eV)
4
28.20 (-eV)
99+
Lattice Constant
291.00 pm
99+
300.50 pm
99+
Lattice Angles
π/2, π/2, π/2
NA
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
7.19 g/cm3
99+
13.53 g/cm3
24
Density When Liquid (at m.p.)
6.30 g/cm3
40
Not Available
Tensile Strength
689.00 MPa
7
Not Available
Viscosity
Not Available
0.00
1
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)
24
Not Available
Vapor Pressure at 2000 K
774.00 (Pa)
1
Not Available
Elasticity properties
Shear Modulus
115.00 GPa
9
Not Available
Bulk Modulus
160.00 GPa
11
Not Available
Young's Modulus
279.00 GPa
8
Not Available
Poisson Ratio
0.21
32
Not Available
Other Mechanical Properties
NA
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
7.19
99+
13.53
16
Magnetic Ordering
Antiferromagnetic
Diamagnetic
Electrical Properties
Electrical Property
NA
Conductor
Resistivity
125.00 nΩ·m
27
961.00 nΩ·m
1
Electrical Conductivity
0.08 106/cm Ω
25
0.01 106/cm Ω
99+
Electron Affinity
64.30 kJ/mol
15
0.00 kJ/mol
40
Thermal Properties
Specific Heat
0.45 J/(kg K)
12
0.14 J/(kg K)
38
Molar Heat Capacity
23.35 J/mol·K
99+
27.98 J/mol·K
13
Thermal Conductivity
93.90 W/m·K
17
8.30 W/m·K
99+
Critical Temperature
Not Available
1,750.00 K
6
Thermal Expansion
4.90 µm/(m·K)
99+
60.40 µm/(m·K)
5
Enthalpy
Enthalpy of Vaporization
348.80 kJ/mol
24
56.90 kJ/mol
99+
Enthalpy of Fusion
15.31 kJ/mol
20
2.29 kJ/mol
99+
Enthalpy of Atomization
397.50 kJ/mol
21
61.50 kJ/mol
99+
Standard Molar Entropy
23.80 J/mol.K
99+
75.80 J/mol.K
6
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