Properties of Niobium and Lead
Boiling Point
2,468.00 °C
  
99+
1,740.00 °C
  
99+
Hardness
  
  
Vickers Hardness
Not Available
  
Optical Properties
  
  
Refractive Index
Not Available
  
Not Available
  
Reflectivity
Not Available
  
Not Available
  
Speed of Sound
3,480.00 m/s
  
21
1,190.00 m/s
  
99+
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Nb
  
Pb
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
652.10 kJ/mol
  
99+
715.60 kJ/mol
  
31
2nd Energy Level
1,380.00 kJ/mol
  
99+
1,450.50 kJ/mol
  
99+
3rd Energy Level
2,416.00 kJ/mol
  
99+
3,081.50 kJ/mol
  
23
Electrochemical Equivalent
0.69 g/amp-hr
  
99+
3.87 g/amp-hr
  
9
Other Chemical Properties
Density
  
  
Density At Room Temperature
8.57 g/cm3
  
99+
11.34 g/cm3
  
33
Density When Liquid (at m.p.)
Not Available
  
10.66 g/cm3
  
15
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Viscosity
Not Available
  
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Symbol
Nb
  
Pb
  
Period Number
5
  
6
  
Atomic Volume
10.87 cm3/mol
  
99+
18.17 cm3/mol
  
27
Electron Configuration
[Kr] 4d4 5s1
  
[Xe] 4f14 5d10 6s2 6p2
  
Valence Electron Potential
104.00 (-eV)
  
8
24.20 (-eV)
  
99+
Atom
  
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
FCC-Crystal-Structure-of-Lead.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
152.00 nΩ·m
  
23
208.00 nΩ·m
  
16
Electrical Conductivity
0.07 106/cm Ω
  
28
0.05 106/cm Ω
  
36
Electron Affinity
86.10 kJ/mol
  
12
35.10 kJ/mol
  
28
Magnetic Characteristics
  
  
Permeability
Not Available
  
Not Available
  
Susceptibility
Not Available
  
Not Available
  
Specific Heat
0.26 J/(kg K)
  
20
0.13 J/(kg K)
  
39
Thermal Conductivity
53.70 W/m·K
  
29
35.30 W/m·K
  
38
Critical Temperature
Not Available
  
Not Available
  
Molar Heat Capacity
24.60 J/mol·K
  
99+
26.65 J/mol·K
  
26
Thermal Expansion
7.30 µm/(m·K)
  
99+
28.90 µm/(m·K)
  
13
Standard Molar Entropy
36.40 J/mol.K
  
99+
64.80 J/mol.K
  
17
Enthalpy
  
  
Enthalpy of Vaporization
696.60 kJ/mol
  
4
179.40 kJ/mol
  
99+
Enthalpy of Fusion
27.20 kJ/mol
  
6
4.77 kJ/mol
  
99+
Enthalpy of Atomization
745.00 kJ/mol
  
4
194.60 kJ/mol
  
99+