Properties of Rhodium and Tantalum
Melting Point
1,966.00 °C
  
12
Boiling Point
3,727.00 °C
  
17
Hardness
  
  
Vickers Hardness
1,100.00 MPa
  
9
Optical Properties
  
  
Refractive Index
Not Available
  
Not Available
  
Speed of Sound
4,700.00 m/s
  
15
3,400.00 m/s
  
22
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Rh
  
Ta
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
719.70 kJ/mol
  
29
761.00 kJ/mol
  
18
2nd Energy Level
1,740.00 kJ/mol
  
26
1,500.00 kJ/mol
  
40
3rd Energy Level
2,997.00 kJ/mol
  
27
Not Available
  
Electrochemical Equivalent
1.28 g/amp-hr
  
99+
1.35 g/amp-hr
  
99+
Other Chemical Properties
Density
  
  
Density At Room Temperature
12.41 g/cm3
  
28
16.69 g/cm3
  
18
Density When Liquid (at m.p.)
10.70 g/cm3
  
14
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Not Available
  
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Symbol
Rh
  
Ta
  
Period Number
5
  
6
  
Atomic Weight
102.91 amu
  
99+
Atomic Volume
8.30 cm3/mol
  
99+
10.90 cm3/mol
  
99+
Electron Configuration
[Kr] 4d8 5s1
  
[Xe] 4f14 5d3 6s2
  
Valence Electron Potential
64.00 (-eV)
  
22
110.00 (-eV)
  
7
Atom
  
  
Crystal Lattice
FCC-Crystal-Structure-of-Rhodium.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Radius of an Atom
  
  
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Adjacent Atomic Numbers
  
  
Electrical Properties
  
  
Resistivity
43.30 nΩ·m
  
99+
131.00 nΩ·m
  
25
Electrical Conductivity
0.21 106/cm Ω
  
8
0.08 106/cm Ω
  
27
Electron Affinity
109.70 kJ/mol
  
7
31.00 kJ/mol
  
29
Magnetic Characteristics
  
  
Permeability
Not Available
  
Not Available
  
Susceptibility
Not Available
  
Not Available
  
Specific Heat
0.24 J/(kg K)
  
22
0.14 J/(kg K)
  
37
Thermal Conductivity
150.00 W/m·K
  
9
57.50 W/m·K
  
27
Critical Temperature
Not Available
  
Not Available
  
Molar Heat Capacity
24.98 J/mol·K
  
99+
25.36 J/mol·K
  
99+
Thermal Expansion
8.20 µm/(m·K)
  
99+
6.30 µm/(m·K)
  
99+
Standard Molar Entropy
31.50 J/mol.K
  
99+
41.50 J/mol.K
  
37
Enthalpy
  
  
Enthalpy of Vaporization
495.40 kJ/mol
  
12
753.10 kJ/mol
  
2
Enthalpy of Fusion
21.76 kJ/mol
  
10
31.40 kJ/mol
  
3
Enthalpy of Atomization
556.50 kJ/mol
  
12
782.00 kJ/mol
  
3