Properties of Rhodium and Cobalt
Melting Point
1,966.00 °C
  
12
1,495.00 °C
  
29
Boiling Point
3,727.00 °C
  
17
2,870.00 °C
  
34
Hardness
  
  
Vickers Hardness
1,100.00 MPa
  
9
1,043.00 MPa
  
11
Optical Properties
  
  
Refractive Index
Not Available
  
Not Available
  
Speed of Sound
4,700.00 m/s
  
15
4,720.00 m/s
  
14
Allotropes
No
  
Yes
  
α Allotropes
Not Available
  
β Allotropes
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Rh
  
Co
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
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
760.40 kJ/mol
  
19
2nd Energy Level
1,740.00 kJ/mol
  
26
1,648.00 kJ/mol
  
31
3rd Energy Level
2,997.00 kJ/mol
  
27
3,232.00 kJ/mol
  
22
Electrochemical Equivalent
1.28 g/amp-hr
  
99+
1.10 g/amp-hr
  
99+
Other Chemical Properties
Density
  
  
Density At Room Temperature
12.41 g/cm3
  
28
4.51 g/cm3
  
99+
Density When Liquid (at m.p.)
10.70 g/cm3
  
14
4.11 g/cm3
  
99+
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Symbol
Rh
  
Co
  
Period Number
5
  
4
  
Atomic Weight
102.91 amu
  
99+
Atomic Volume
8.30 cm3/mol
  
99+
10.64 cm3/mol
  
99+
Electron Configuration
[Kr] 4d8 5s1
  
[Ar] 3d2 4s2
  
Valence Electron Potential
64.00 (-eV)
  
22
95.20 (-eV)
  
10
Atom
  
  
Crystal Lattice
FCC-Crystal-Structure-of-Rhodium.jpg#100
  
HCP-Crystal-Structure-of-Cobalt.jpg#100
  
Radius of an Atom
  
  
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, 2 π/3
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Adjacent Atomic Numbers
  
  
Electrical Properties
  
  
Resistivity
43.30 nΩ·m
  
99+
420.00 nΩ·m
  
12
Electrical Conductivity
0.21 106/cm Ω
  
8
0.02 106/cm Ω
  
99+
Electron Affinity
109.70 kJ/mol
  
7
7.60 kJ/mol
  
37
Magnetic Characteristics
  
  
Permeability
Not Available
  
Not Available
  
Susceptibility
Not Available
  
Not Available
  
Specific Heat
0.24 J/(kg K)
  
22
0.52 J/(kg K)
  
9
Thermal Conductivity
150.00 W/m·K
  
9
21.90 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Molar Heat Capacity
24.98 J/mol·K
  
99+
25.06 J/mol·K
  
99+
Thermal Expansion
8.20 µm/(m·K)
  
99+
8.60 µm/(m·K)
  
99+
Standard Molar Entropy
31.50 J/mol.K
  
99+
27.30 J/mol.K
  
99+
Enthalpy
  
  
Enthalpy of Vaporization
495.40 kJ/mol
  
12
429.00 kJ/mol
  
15
Enthalpy of Fusion
21.76 kJ/mol
  
10
15.48 kJ/mol
  
19
Enthalpy of Atomization
556.50 kJ/mol
  
12
468.60 kJ/mol
  
15