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Rhodium vs Neptunium


Neptunium vs Rhodium


Periodic Table

Symbol
Rh   
Np   

Group Number
9   
9
Not Available   

Period Number
5   
7   

Block
d block   
f block   

Element Family
Transition Metal   
Actinide   

CAS Number
7440166   
99+
7439998   
99+

Space Group Name
Fm_ 3m   
Pnma   

Space Group Number
225.00   
2
62.00   
11

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   
Made by Bombarding Uranium with Neutrons, Ores of metals   

History
  
  

Who Discovered
William Hyde Wollaston   
Edwin McMillan and Philip H. Abelson   

Discovery
In 1804   
In 1940   

Abundance
  
  

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

Abundance In Sun
~0.0000002 %   
25
~-9999 %   

Abundance In Meteorites
0.00 %   
36
Not Available   

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

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.
  
  • Currently known uses of Neptunium metal are limited to research purpose only.
  • Neptunium’s isotope neptunium-237 is used as a neutron detectors.
  

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

Medical Uses
NA   
NA   

Other Uses
Alloys   
Alloys, Nuclear Research, Research Purposes   

Biological Properties
  
  

Toxicity
NA   
Toxic   

Present in Human Body
No   
No   

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

In Bone
Not Available   
0.00 p.p.m.   
36

Physical Properties

Melting Point
1,966.00 °C   
12
640.00 °C   
99+

Boiling Point
3,727.00 °C   
17
3,902.00 °C   
13

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Silver   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
6.00   
6
Not Available   

Brinell Hardness
980.00 MPa   
9
Not Available   

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   
Np   

Isotopes
  
  

Known Isotopes
16   
23
20   
19

Electronegativity
  
  

Pauling Electronegativity
2.28   
3
1.36   
29

Allred Rochow Electronegativity
1.45   
16
1.22   
26

Allen Electronegativity
1.56   
24
Not Available   

Electropositivity
  
  

Pauling Electropositivity
1.72   
99+
2.64   
25

Ionization Energies
  
  

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

2nd Energy Level
1,740.00 kJ/mol   
26
1,128.00 kJ/mol   
99+

3rd Energy Level
2,997.00 kJ/mol   
27
1,997.00 kJ/mol   
99+

4th Energy Level
Not Available   
3,242.00 kJ/mol   
99+

Electrochemical Equivalent
1.28 g/amp-hr   
99+
1.77 g/amp-hr   
39

Electron Work Function
4.98 eV   
6
Not Available   

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

Atomic Properties

Atomic Number
45   
99+
93   
25

Electron Configuration
[Kr] 4d8 5s1   
[Rn] 5f4 6d1 7s2   

Crystal Structure
Face Centered Cubic (FCC)   
Orthorhombic (ORTH)   

Crystal Lattice
FCC-Crystal-Structure-of-Rhodium.jpg#100   
ORTH-Crystal-Structure-of-Neptunium.jpg#100   

Atom
  
  

Number of Protons
45   
99+
93   
25

Number of Neutrons
58   
99+
144   
14

Number of Electrons
45   
99+
93   
25

Radius of an Atom
  
  

Atomic Radius
134.00 pm   
99+
155.00 pm   
30

Covalent Radius
142.00 pm   
99+
190.00 pm   
18

Van der Waals Radius
200.00 pm   
28
221.00 pm   
22

Atomic Weight
102.91 amu   
99+
237.00 amu   
22

Atomic Volume
8.30 cm3/mol   
99+
11.62 cm3/mol   
99+

Adjacent Atomic Numbers
  
  

Previous Element
Ruthenium
  
Uranium
  

Next Element
Palladium
  
Plutonium
  

Valence Electron Potential
64.00 (-eV)   
22
96.00 (-eV)   
9

Lattice Constant
380.34 pm   
27
666.30 pm   
3

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
19.38 g/cm3   
14

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

Tensile Strength
951.00 MPa   
5
125.00 MPa   
14

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
0.02 (Pa)   
19
0.11 (Pa)   
17

Elasticity properties
  
  

Shear Modulus
150.00 GPa   
6
Not Available   

Bulk Modulus
275.00 GPa   
5
Not Available   

Young's Modulus
380.00 GPa   
5
Not Available   

Poisson Ratio
0.26   
22
Not Available   

Other Mechanical Properties
Malleable   
Ductile   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
12.41   
20
20.25   
6

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
43.30 nΩ·m   
99+
1.22 nΩ·m   
99+

Electrical Conductivity
0.21 106/cm Ω   
8
0.01 106/cm Ω   
99+

Electron Affinity
109.70 kJ/mol   
7
Not Available   

Thermal Properties

Specific Heat
0.24 J/(kg K)   
22
0.12 J/(kg K)   
40

Molar Heat Capacity
24.98 J/mol·K   
99+
29.46 J/mol·K   
8

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
8.20 µm/(m·K)   
99+
Not Available   

Enthalpy
  
  

Enthalpy of Vaporization
495.40 kJ/mol   
12
Not Available   

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

Enthalpy of Atomization
556.50 kJ/mol   
12
Not Available   

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

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