Properties of Neodymium and Praseodymium
Melting Point
1,010.00 °C
  
99+
Boiling Point
3,127.00 °C
  
28
3,130.00 °C
  
27
Hardness
  
  
Mohs Hardness
Not Available
  
Not Available
  
Optical Properties
  
  
Refractive Index
Not Available
  
Not Available
  
Reflectivity
Not Available
  
Not Available
  
Speed of Sound
2,330.00 m/s
  
38
2,280.00 m/s
  
40
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Nd
  
Pr
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Not Available
  
Allen Electronegativity
Not Available
  
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
533.10 kJ/mol
  
99+
527.00 kJ/mol
  
99+
2nd Energy Level
1,040.00 kJ/mol
  
99+
1,020.00 kJ/mol
  
99+
3rd Energy Level
2,130.00 kJ/mol
  
99+
2,086.00 kJ/mol
  
99+
Electrochemical Equivalent
1.79 g/amp-hr
  
37
1.75 g/amp-hr
  
40
Other Chemical Properties
Density
  
  
Density At Room Temperature
7.01 g/cm3
  
99+
6.77 g/cm3
  
99+
Density When Liquid (at m.p.)
Vapor Pressure
  
  
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
NA
  
Symbol
Nd
  
Pr
  
Group Number
Not Available
  
Period Number
6
  
6
  
Atomic Weight
144.24 amu
  
99+
140.91 amu
  
99+
Atomic Volume
20.60 cm3/mol
  
18
20.80 cm3/mol
  
15
Electron Configuration
[Xe] 4f4 6s2
  
[Xe] 4f3 6s2
  
Valence Electron Potential
43.40 (-eV)
  
99+
42.64 (-eV)
  
99+
Atom
  
  
Crystal Lattice
DHCP-Crystal-Structure-of-Neodymium.jpg#100
  
HCP-Crystal-Structure-of-Praseodymium.jpg#100
  
Radius of an Atom
  
  
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, 2 π/3
  
Adjacent Atomic Numbers
  
  
Electrical Properties
  
  
Electrical Conductivity
0.02 106/cm Ω
  
99+
0.01 106/cm Ω
  
99+
Electron Affinity
50.00 kJ/mol
  
21
50.00 kJ/mol
  
21
Electrical Property
NA
  
Magnetic Characteristics
  
  
Permeability
Not Available
  
Not Available
  
Susceptibility
Not Available
  
Not Available
  
Specific Heat
0.19 J/(kg K)
  
32
0.19 J/(kg K)
  
32
Thermal Conductivity
16.50 W/m·K
  
99+
12.50 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Molar Heat Capacity
27.45 J/mol·K
  
17
27.20 J/mol·K
  
18
Thermal Expansion
9.60 µm/(m·K)
  
99+
6.70 µm/(m·K)
  
99+
Standard Molar Entropy
71.50 J/mol.K
  
13
73.20 J/mol.K
  
10
Enthalpy
  
  
Enthalpy of Vaporization
273.00 kJ/mol
  
34
296.80 kJ/mol
  
29
Enthalpy of Fusion
7.14 kJ/mol
  
99+
6.89 kJ/mol
  
99+
Enthalpy of Atomization
322.00 kJ/mol
  
32
368.00 kJ/mol
  
24