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Promethium Rhodium Comparison


Rhodium Promethium comparison


Periodic Table

Symbol
Pm   
Rh   

Group Number
Not Available   
9   
9

Period Number
6   
5   

Block
f block   
d block   

Element Family
Lanthanide   
Transition Metal   

CAS Number
7440122   
99+
7440166   
99+

Space Group Name
Not Available   
Fm_ 3m   

Space Group Number
Not Available   
225.00   
2

Facts

Interesting Facts
  • Promethium metal found in Pitchblende.
  • Promethium metal is highly radioactive metal.
  
  • 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.
  

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

History
  
  

Who Discovered
Chien Shiung Wu, Emilio Segrè, Hans Bethe   
William Hyde Wollaston   

Discovery
In 1942   
In 1804   

Abundance
  
  

Abundance In Universe
Not Available   
6 * 10-8 %   
26

Abundance In Sun
~-9999 %   
~0.0000002 %   
25

Abundance In Meteorites
Not Available   
0.00 %   
36

Abundance In Earth's Crust
Not Available   
0.00 %   
99+

Uses

Uses & Benefits
  • It is used for research purpose. Very small amount of this metal is used in atomic batteries.
  • Its radioactive decay is used for a phosphor to give off light. The light emitted is converted into electricity.
  
  • 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.
  

Industrial Uses
NA   
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry   

Medical Uses
NA   
NA   

Other Uses
NA   
Alloys   

Biological Properties
  
  

Toxicity
Non Toxic   
NA   

Present in Human Body
No   
No   

In Blood
0.00 Blood/mg dm-3   
37
Not Available   

Physical Properties

Melting Point
1,042.00 °C   
99+
1,966.00 °C   
12

Boiling Point
3,000.00 °C   
31
3,727.00 °C   
17

Appearance
  
  

Physical State
Solid   
Solid   

Color
Unknown   
Silvery White   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
Not Available   
6.00   
6

Brinell Hardness
Not Available   
980.00 MPa   
9

Vickers Hardness
Not Available   
1,100.00 MPa   
9

Speed of Sound
Not Available   
4,700.00 m/s   
15

Optical Properties
  
  

Reflectivity
Not Available   
84.00 %   
4

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
Pm   
Rh   

Isotopes
  
  

Known Isotopes
27   
12
16   
23

Electronegativity
  
  

Pauling Electronegativity
Not Available   
2.28   
3

Allred Rochow Electronegativity
1.07   
32
1.45   
16

Allen Electronegativity
Not Available   
1.56   
24

Electropositivity
  
  

Pauling Electropositivity
Not Available   
1.72   
99+

Ionization Energies
  
  

1st Energy Level
540.00 kJ/mol   
99+
719.70 kJ/mol   
29

2nd Energy Level
1,050.00 kJ/mol   
99+
1,740.00 kJ/mol   
26

3rd Energy Level
2,150.00 kJ/mol   
99+
2,997.00 kJ/mol   
27

4th Energy Level
3,970.00 kJ/mol   
38
Not Available   

Electrochemical Equivalent
1.80 g/amp-hr   
36
1.28 g/amp-hr   
99+

Electron Work Function
Not Available   
4.98 eV   
6

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

Atomic Properties

Atomic Number
61   
99+
45   
99+

Electron Configuration
[Xe] 4f5 6s2   
[Kr] 4d8 5s1   

Crystal Structure
Double Hexagonal Close Packed (DHCP)   
Face Centered Cubic (FCC)   

Crystal Lattice
DHCP-Crystal-Structure-of-Promethium.jpg#100   
FCC-Crystal-Structure-of-Rhodium.jpg#100   

Atom
  
  

Number of Protons
61   
99+
45   
99+

Number of Neutrons
84   
40
58   
99+

Number of Electrons
61   
99+
45   
99+

Radius of an Atom
  
  

Atomic Radius
183.00 pm   
10
134.00 pm   
99+

Covalent Radius
199.00 pm   
12
142.00 pm   
99+

Van der Waals Radius
236.00 pm   
16
200.00 pm   
28

Atomic Weight
145.00 amu   
99+
102.91 amu   
99+

Atomic Volume
22.39 cm3/mol   
12
8.30 cm3/mol   
99+

Adjacent Atomic Numbers
  
  

Previous Element
Neodymium
  
Ruthenium
  

Next Element
Samarium
  
Palladium
  

Valence Electron Potential
44.10 (-eV)   
39
64.00 (-eV)   
22

Lattice Constant
Not Available   
380.34 pm   
27

Lattice Angles
Unknown   
π/2, π/2, π/2   

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

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

Density When Liquid (at m.p.)
Not Available   
10.70 g/cm3   
14

Tensile Strength
Not Available   
951.00 MPa   
5

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
Not Available   
0.02 (Pa)   
19

Elasticity properties
  
  

Shear Modulus
18.00 GPa   
36
150.00 GPa   
6

Bulk Modulus
33.00 GPa   
36
275.00 GPa   
5

Young's Modulus
46.00 GPa   
38
380.00 GPa   
5

Poisson Ratio
0.28   
17
0.26   
22

Other Mechanical Properties
NA   
Malleable   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
7.26   
99+
12.41   
20

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
0.75 nΩ·m   
99+
43.30 nΩ·m   
99+

Electrical Conductivity
Not Available   
0.21 106/cm Ω   
8

Electron Affinity
50.00 kJ/mol   
21
109.70 kJ/mol   
7

Thermal Properties

Specific Heat
0.18 J/(kg K)   
33
0.24 J/(kg K)   
22

Molar Heat Capacity
Not Available   
24.98 J/mol·K   
99+

Thermal Conductivity
17.90 W/m·K   
99+
150.00 W/m·K   
9

Critical Temperature
Not Available   
Not Available   

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

Enthalpy
  
  

Enthalpy of Vaporization
Not Available   
495.40 kJ/mol   
12

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

Enthalpy of Atomization
310.00 kJ/mol   
34
556.50 kJ/mol   
12

Standard Molar Entropy
Not Available   
31.50 J/mol.K   
99+

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