Rhodium Cesium Comparison
Periodic Table
Symbol
Rh
Cs
Group Number
9
9
1
17
Period Number
5
6
Block
d block
s block
Element Family
Transition Metal
Alkali
CAS Number
7440166
99+
7440462
40
Space Group Name
Fm_ 3m
Im_ 3m
Space Group Number
225.00
2
229.00
1
Facts
Interesting Facts
- Rhodium is the rarest element out of all non-radioactive metals on the earth .
- Rhodium is one of the most durable and hard metal, which also have high reflectance.
Not Available
Sources
Earth's crust, Found As a By-product, Found in Minerals, Mining
Earth's crust, Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
William Hyde Wollaston
Robert Bunsen and Gustav Kirchhoff
Discovery
In 1804
In 1860
Abundance
Abundance In Universe
6 * 10-8 %
26
8 * 10-8 %
24
Abundance In Sun
~0.0000002 %
25
~0.0000008 %
20
Abundance In Meteorites
0.00 %
36
0.00 %
38
Abundance In Earth's Crust
0.00 %
99+
0.00 %
35
Abundance In Oceans
Not Available
0.00 %
17
Abundance In Humans
Not Available
0.00 %
17
Uses
Uses & Benefits
- Rhodium metal is mainly used in catalytic converters for cars as it reduces nitrogen oxides in exhaust gases.
- It is used as an industrial catalyst for nitric acid, acetic acid, hydrogenation reaction, etc.
- The most common use of cesium metal is as a drilling fluid. It is also used in optical glass manufacturing.
- In vacuum tubes and radiation monitor equipment this metal is used as a catalyst promoter.
Industrial Uses
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
NA
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
NA
Mildly Toxic
Present in Human Body
No
Yes
In Blood
Not Available
0.00 Blood/mg dm-3
28
In Bone
Not Available
0.05 p.p.m.
26
Physical Properties
Melting Point
1,966.00 °C
12
28.50 °C
99+
Boiling Point
3,727.00 °C
17
678.40 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery Gold
Luster
Metallic
NA
Hardness
Mohs Hardness
6.00
6
0.20
25
Brinell Hardness
980.00 MPa
9
0.14 MPa
99+
Vickers Hardness
1,100.00 MPa
9
Not Available
Speed of Sound
4,700.00 m/s
15
Not Available
Optical Properties
Reflectivity
84.00 %
4
Not Available
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
Rh
Cs
Isotopes
Known Isotopes
16
23
36
3
Electronegativity
Pauling Electronegativity
2.28
3
0.79
99+
Sanderson Electronegativity
Not Available
0.22
33
Allred Rochow Electronegativity
1.45
16
0.86
99+
Mulliken-Jaffe Electronegativity
Not Available
0.62
26
Allen Electronegativity
1.56
24
0.66
99+
Electropositivity
Pauling Electropositivity
1.72
99+
3.21
2
Ionization Energies
1st Energy Level
719.70 kJ/mol
29
375.70 kJ/mol
99+
2nd Energy Level
1,740.00 kJ/mol
26
2,234.30 kJ/mol
8
3rd Energy Level
2,997.00 kJ/mol
27
3,400.00 kJ/mol
16
Electrochemical Equivalent
1.28 g/amp-hr
99+
4.96 g/amp-hr
3
Electron Work Function
4.98 eV
6
2.14 eV
99+
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes
Chemical Stability, Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
45
99+
55
99+
Electron Configuration
[Kr] 4d8 5s1
[Xe] 6s1
Crystal Structure
Face Centered Cubic (FCC)
Body Centered Cubic (BCC)
Crystal Lattice
FCC-Crystal-Structure-of-Rhodium.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
45
99+
55
99+
Number of Neutrons
58
99+
78
99+
Number of Electrons
45
99+
55
99+
Radius of an Atom
Atomic Radius
134.00 pm
99+
265.00 pm
1
Covalent Radius
142.00 pm
99+
244.00 pm
2
Van der Waals Radius
200.00 pm
28
343.00 pm
2
Atomic Weight
102.91 amu
99+
132.91 amu
99+
Atomic Volume
8.30 cm3/mol
99+
71.07 cm3/mol
1
Adjacent Atomic Numbers
Valence Electron Potential
64.00 (-eV)
22
8.62 (-eV)
99+
Lattice Constant
380.34 pm
27
614.10 pm
5
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
12.41 g/cm3
28
1.93 g/cm3
99+
Density When Liquid (at m.p.)
10.70 g/cm3
14
1.84 g/cm3
99+
Tensile Strength
951.00 MPa
5
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 2000 K
0.02 (Pa)
19
Not Available
Elasticity properties
Shear Modulus
150.00 GPa
6
Not Available
Bulk Modulus
275.00 GPa
5
1.60 GPa
99+
Young's Modulus
380.00 GPa
5
1.70 GPa
99+
Poisson Ratio
0.26
22
Not Available
Other Mechanical Properties
Malleable
Ductile
Magnetic Properties
Magnetic Characteristics
Specific Gravity
12.41
20
1.87
99+
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Semiconductor
Resistivity
43.30 nΩ·m
99+
205.00 nΩ·m
17
Electrical Conductivity
0.21 106/cm Ω
8
0.05 106/cm Ω
35
Electron Affinity
109.70 kJ/mol
7
45.50 kJ/mol
25
Thermal Properties
Specific Heat
0.24 J/(kg K)
22
0.24 J/(kg K)
23
Molar Heat Capacity
24.98 J/mol·K
99+
32.21 J/mol·K
4
Thermal Conductivity
150.00 W/m·K
9
35.90 W/m·K
36
Critical Temperature
Not Available
1,938.00 K
5
Thermal Expansion
8.20 µm/(m·K)
99+
97.00 µm/(m·K)
1
Enthalpy
Enthalpy of Vaporization
495.40 kJ/mol
12
65.90 kJ/mol
99+
Enthalpy of Fusion
21.76 kJ/mol
10
2.10 kJ/mol
99+
Enthalpy of Atomization
556.50 kJ/mol
12
78.20 kJ/mol
99+
Standard Molar Entropy
31.50 J/mol.K
99+
85.20 J/mol.K
3
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