Properties of Praseodymium and Rhodium
Melting Point
1,966.00 °C
  
12
Boiling Point
3,130.00 °C
  
27
3,727.00 °C
  
17
Hardness
  
  
Mohs Hardness
Not Available
  
Vickers Hardness
1,100.00 MPa
  
9
Optical Properties
  
  
Refractive Index
Not Available
  
Not Available
  
Reflectivity
Not Available
  
Speed of Sound
2,280.00 m/s
  
40
4,700.00 m/s
  
15
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Pr
  
Rh
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Not Available
  
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
527.00 kJ/mol
  
99+
719.70 kJ/mol
  
29
2nd Energy Level
1,020.00 kJ/mol
  
99+
1,740.00 kJ/mol
  
26
3rd Energy Level
2,086.00 kJ/mol
  
99+
2,997.00 kJ/mol
  
27
Electrochemical Equivalent
1.75 g/amp-hr
  
40
1.28 g/amp-hr
  
99+
Other Chemical Properties
Density
  
  
Density At Room Temperature
6.77 g/cm3
  
99+
12.41 g/cm3
  
28
Density When Liquid (at m.p.)
10.70 g/cm3
  
14
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Symbol
Pr
  
Rh
  
Group Number
Not Available
  
Period Number
6
  
5
  
Atomic Weight
140.91 amu
  
99+
102.91 amu
  
99+
Atomic Volume
20.80 cm3/mol
  
15
8.30 cm3/mol
  
99+
Electron Configuration
[Xe] 4f3 6s2
  
[Kr] 4d8 5s1
  
Valence Electron Potential
42.64 (-eV)
  
99+
64.00 (-eV)
  
22
Atom
  
  
Crystal Lattice
HCP-Crystal-Structure-of-Praseodymium.jpg#100
  
FCC-Crystal-Structure-of-Rhodium.jpg#100
  
Radius of an Atom
  
  
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Adjacent Atomic Numbers
  
  
Electrical Properties
  
  
Resistivity
43.30 nΩ·m
  
99+
Electrical Conductivity
0.01 106/cm Ω
  
99+
0.21 106/cm Ω
  
8
Electron Affinity
50.00 kJ/mol
  
21
109.70 kJ/mol
  
7
Magnetic Characteristics
  
  
Permeability
Not Available
  
Not Available
  
Susceptibility
Not Available
  
Not Available
  
Specific Heat
0.19 J/(kg K)
  
32
0.24 J/(kg K)
  
22
Thermal Conductivity
12.50 W/m·K
  
99+
150.00 W/m·K
  
9
Critical Temperature
Not Available
  
Not Available
  
Molar Heat Capacity
27.20 J/mol·K
  
18
24.98 J/mol·K
  
99+
Thermal Expansion
6.70 µm/(m·K)
  
99+
8.20 µm/(m·K)
  
99+
Standard Molar Entropy
73.20 J/mol.K
  
10
31.50 J/mol.K
  
99+
Enthalpy
  
  
Enthalpy of Vaporization
296.80 kJ/mol
  
29
495.40 kJ/mol
  
12
Enthalpy of Fusion
6.89 kJ/mol
  
99+
21.76 kJ/mol
  
10
Enthalpy of Atomization
368.00 kJ/mol
  
24
556.50 kJ/mol
  
12