Properties of Hafnium and Holmium
Melting Point
2,150.00 °C
  
10
1,461.00 °C
  
30
Boiling Point
2,600.00 °C
  
99+
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
1,450.00 MPa
  
6
Vickers Hardness
1,520.00 MPa
  
5
Optical Properties
  
  
Refractive Index
Not Available
  
Not Available
  
Reflectivity
Not Available
  
Not Available
  
Speed of Sound
3,010.00 m/s
  
27
2,760.00 m/s
  
30
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Hf
  
Ho
  
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
658.50 kJ/mol
  
40
581.00 kJ/mol
  
99+
2nd Energy Level
1,440.00 kJ/mol
  
99+
1,140.00 kJ/mol
  
99+
3rd Energy Level
2,250.00 kJ/mol
  
99+
2,204.00 kJ/mol
  
99+
Electrochemical Equivalent
1.66 g/amp-hr
  
99+
2.02 g/amp-hr
  
29
Electron Work Function
Not Available
  
Other Chemical Properties
Density
  
  
Density At Room Temperature
13.31 g/cm3
  
26
8.79 g/cm3
  
99+
Density When Liquid (at m.p.)
12.00 g/cm3
  
12
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Vapor Pressure at 2000 K
Not Available
  
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Symbol
Hf
  
Ho
  
Group Number
Not Available
  
Period Number
6
  
6
  
Atomic Weight
164.93 amu
  
99+
Atomic Volume
13.60 cm3/mol
  
38
18.70 cm3/mol
  
24
Electron Configuration
[Xe] 4f14 5d2 6s2
  
[Xe] 4f11 6s2
  
Valence Electron Potential
81.00 (-eV)
  
16
47.90 (-eV)
  
31
Atom
  
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
HCP-Crystal-Structure-of-Holmium.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
  
  
Resistivity
331.00 nΩ·m
  
14
Electrical Conductivity
0.03 106/cm Ω
  
39
0.01 106/cm Ω
  
99+
Electron Affinity
0.00 kJ/mol
  
40
50.00 kJ/mol
  
21
Magnetic Characteristics
  
  
Permeability
Not Available
  
Not Available
  
Susceptibility
Not Available
  
Not Available
  
Specific Heat
0.14 J/(kg K)
  
37
0.16 J/(kg K)
  
35
Thermal Conductivity
23.00 W/m·K
  
99+
16.20 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Molar Heat Capacity
25.73 J/mol·K
  
36
27.15 J/mol·K
  
19
Thermal Expansion
5.90 µm/(m·K)
  
99+
11.20 µm/(m·K)
  
35
Standard Molar Entropy
43.60 J/mol.K
  
34
75.30 J/mol.K
  
8
Enthalpy
  
  
Enthalpy of Vaporization
661.10 kJ/mol
  
5
241.00 kJ/mol
  
38
Enthalpy of Fusion
25.10 kJ/mol
  
8
11.76 kJ/mol
  
29
Enthalpy of Atomization
703.00 kJ/mol
  
5
301.00 kJ/mol
  
36