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Rhodium Cadmium Comparison


Cadmium Rhodium comparison


Periodic Table

Symbol
Rh   
Cd   

Group Number
9   
9
12   
6

Period Number
5   
5   

Block
d block   
d block   

Element Family
Transition Metal   
Transition Metal   

CAS Number
7440166   
99+
7440439   
99+

Space Group Name
Fm_ 3m   
P63/mmc   

Space Group Number
225.00   
2
194.00   
5

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.
  
  • Naturally occurring minor elements include Cadmium.
  • Cadmium is released into atmosphere to control volcanic eruption and forest fires.
  • It is used for electroplating of Steel for corrosion resistance.
  • It can absorb neutrons and used in nuclear reactor to control atomic fission.
  

Sources
Earth's crust, Found As a By-product, Found in Minerals, Mining   
Found As a By-product, Found in Minerals, Mining   

History
  
  

Who Discovered
William Hyde Wollaston   
Karl Samuel Leberecht Hermann and Friedrich Stromeyer   

Discovery
In 1804   
In 1817   

Abundance
  
  

Abundance In Universe
6 * 10-8 %   
26
2 * 10-7 %   
22

Abundance In Sun
~0.0000002 %   
25
~0.0000006 %   
21

Abundance In Meteorites
0.00 %   
36
0.00 %   
31

Abundance In Earth's Crust
0.00 %   
99+
0.00 %   
99+

Abundance In Oceans
Not Available   
0.00 %   
28

Abundance In Humans
Not Available   
0.00 %   
11

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.
  
  • It has very limited uses as it is a toxic metal and it can cause birth defects, cancer, etc.
  • Almost 80% of Cadmium metal is used in Nickel cadmium Batteries and now it is getting replaced with nickel hydride.
  

Industrial Uses
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry   
Aerospace Industry, Ammunition Industry, Chemical Industry, Electrical Industry, Electronic Industry   

Medical Uses
NA   
NA   

Other Uses
Alloys   
Alloys   

Biological Properties
  
  

Toxicity
NA   
Toxic   

Present in Human Body
No   
Yes   

In Blood
Not Available   
0.01 Blood/mg dm-3   
24

In Bone
Not Available   
1.80 p.p.m.   
15

Physical Properties

Melting Point
1,966.00 °C   
12
320.90 °C   
99+

Boiling Point
3,727.00 °C   
17
765.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Silvery Bluish-Gray   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
6.00   
6
2.00   
16

Brinell Hardness
980.00 MPa   
9
203.00 MPa   
39

Vickers Hardness
1,100.00 MPa   
9
Not Available   

Speed of Sound
4,700.00 m/s   
15
2,310.00 m/s   
39

Optical Properties
  
  

Reflectivity
84.00 %   
4
67.00 %   
11

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   
Cd   

Isotopes
  
  

Known Isotopes
16   
23
34   
5

Electronegativity
  
  

Pauling Electronegativity
2.28   
3
1.69   
17

Sanderson Electronegativity
Not Available   
1.98   
9

Allred Rochow Electronegativity
1.45   
16
1.46   
15

Mulliken-Jaffe Electronegativity
Not Available   
1.53   
13

Allen Electronegativity
1.56   
24
1.52   
27

Electropositivity
  
  

Pauling Electropositivity
1.72   
99+
2.31   
37

Ionization Energies
  
  

1st Energy Level
719.70 kJ/mol   
29
867.80 kJ/mol   
11

2nd Energy Level
1,740.00 kJ/mol   
26
1,631.40 kJ/mol   
32

3rd Energy Level
2,997.00 kJ/mol   
27
3,616.00 kJ/mol   
13

Electrochemical Equivalent
1.28 g/amp-hr   
99+
2.10 g/amp-hr   
27

Electron Work Function
4.98 eV   
6
4.22 eV   
22

Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes   
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility   

Atomic Properties

Atomic Number
45   
99+
48   
99+

Electron Configuration
[Kr] 4d8 5s1   
[Kr] 4d10 5s2   

Crystal Structure
Face Centered Cubic (FCC)   
Hexagonal Close Packed (HCP)   

Crystal Lattice
FCC-Crystal-Structure-of-Rhodium.jpg#100   
HCP-Crystal-Structure-of-Cadmium.jpg#100   

Atom
  
  

Number of Protons
45   
99+
48   
99+

Number of Neutrons
58   
99+
64   
99+

Number of Electrons
45   
99+
48   
99+

Radius of an Atom
  
  

Atomic Radius
134.00 pm   
99+
151.00 pm   
32

Covalent Radius
142.00 pm   
99+
144.00 pm   
40

Van der Waals Radius
200.00 pm   
28
158.00 pm   
99+

Atomic Weight
102.91 amu   
99+
112.41 amu   
99+

Atomic Volume
8.30 cm3/mol   
99+
13.10 cm3/mol   
39

Adjacent Atomic Numbers
  
  

Previous Element
Ruthenium
  
Silver
  

Next Element
Palladium
  
Indium
  

Valence Electron Potential
64.00 (-eV)   
22
30.00 (-eV)   
99+

Lattice Constant
380.34 pm   
27
297.94 pm   
99+

Lattice Angles
π/2, π/2, π/2   
π/2, π/2, 2 π/3   

Lattice C/A Ratio
Not Available   
1.89   
1

Mechanical Properties

Density
  
  

Density At Room Temperature
12.41 g/cm3   
28
8.65 g/cm3   
99+

Density When Liquid (at m.p.)
10.70 g/cm3   
14
8.00 g/cm3   
28

Tensile Strength
951.00 MPa   
5
62.00 MPa   
16

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
19.00 GPa   
35

Bulk Modulus
275.00 GPa   
5
42.00 GPa   
29

Young's Modulus
380.00 GPa   
5
50.00 GPa   
36

Poisson Ratio
0.26   
22
0.30   
14

Other Mechanical Properties
Malleable   
Ductile, Malleable   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
12.41   
20
8.65   
36

Magnetic Ordering
Paramagnetic   
Diamagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Semiconductor   

Resistivity
43.30 nΩ·m   
99+
72.70 nΩ·m   
36

Electrical Conductivity
0.21 106/cm Ω   
8
0.14 106/cm Ω   
15

Electron Affinity
109.70 kJ/mol   
7
0.00 kJ/mol   
40

Thermal Properties

Specific Heat
0.24 J/(kg K)   
22
0.23 J/(kg K)   
26

Molar Heat Capacity
24.98 J/mol·K   
99+
26.02 J/mol·K   
32

Thermal Conductivity
150.00 W/m·K   
9
96.60 W/m·K   
16

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
8.20 µm/(m·K)   
99+
30.80 µm/(m·K)   
10

Enthalpy
  
  

Enthalpy of Vaporization
495.40 kJ/mol   
12
100.00 kJ/mol   
99+

Enthalpy of Fusion
21.76 kJ/mol   
10
6.19 kJ/mol   
99+

Enthalpy of Atomization
556.50 kJ/mol   
12
113.00 kJ/mol   
99+

Standard Molar Entropy
31.50 J/mol.K   
99+
51.80 J/mol.K   
27

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