Symbol
Hf
  
Cs
  
Period Number
6
  
6
  
Block
d block
  
s block
  
Element Family
Transition Metal
  
Alkali
  
Space Group Name
P63/mmc
  
Im_ 3m
  
Interesting Facts
- Hafnium metal is highly reactive, hence not found free in nature.
- Hafnium metal as predicated after Mendeleev finished his periodic table.
  
Not Available
  
Sources
By-product Zirconium Refining
  
Earth's crust, Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Dirk Coster and George de Hevesy
  
Robert Bunsen and Gustav Kirchhoff
  
Discovery
In 1922
  
In 1860
  
Abundance
  
  
Abundance In Sun
~0.0000001 %
  
26
~0.0000008 %
  
20
Abundance In Earth's Crust
Abundance In Humans
Not Available
  
Uses & Benefits
- It has an ability to absorb neutrons and hence it is used to make control rods in nuclear submarines. And this metal is also used in Plasma welding torches.
-
It alloys with iron, titanium and niobium are very useful.
  
- The most common use of cesium metal is as a drilling fluid. It is also used in optical glass manufacturing.
-
In vacuum tubes and radiation monitor equipment this metal is used as a catalyst promoter.
  
Industrial Uses
Ammunition Industry
  
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes
  
Alloys
  
Biological Properties
  
  
Toxicity
Toxic
  
Mildly Toxic
  
Present in Human Body
No
  
Yes
  
In Blood
Not Available
  
0.00 Blood/mg dm-3
  
28
In Bone
Not Available
  
0.05 p.p.m.
  
26
Melting Point
2,150.00 °C
  
10
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Silvery Gold
  
Luster
Metallic
  
NA
  
Hardness
  
  
Brinell Hardness
1,450.00 MPa
  
6
Vickers Hardness
1,520.00 MPa
  
5
Not Available
  
Speed of Sound
3,010.00 m/s
  
27
Not Available
  
Optical Properties
  
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Hf
  
Cs
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
658.50 kJ/mol
  
40
375.70 kJ/mol
  
99+
2nd Energy Level
1,440.00 kJ/mol
  
99+
2,234.30 kJ/mol
  
8
3rd Energy Level
2,250.00 kJ/mol
  
99+
3,400.00 kJ/mol
  
16
4th Energy Level
3,216.00 kJ/mol
  
99+
Not Available
  
Electrochemical Equivalent
1.66 g/amp-hr
  
99+
4.96 g/amp-hr
  
3
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Chemical Stability, Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Xe] 4f14 5d2 6s2
  
[Xe] 6s1
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
132.91 amu
  
99+
Atomic Volume
13.60 cm3/mol
  
38
71.07 cm3/mol
  
1
Adjacent Atomic Numbers
  
  
Valence Electron Potential
81.00 (-eV)
  
16
8.62 (-eV)
  
99+
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
13.31 g/cm3
  
26
1.93 g/cm3
  
99+
Density When Liquid (at m.p.)
12.00 g/cm3
  
12
1.84 g/cm3
  
99+
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile, Malleable
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Semiconductor
  
Resistivity
331.00 nΩ·m
  
14
205.00 nΩ·m
  
17
Electrical Conductivity
0.03 106/cm Ω
  
39
0.05 106/cm Ω
  
35
Electron Affinity
0.00 kJ/mol
  
40
45.50 kJ/mol
  
25
Specific Heat
0.14 J/(kg K)
  
37
0.24 J/(kg K)
  
23
Molar Heat Capacity
25.73 J/mol·K
  
36
32.21 J/mol·K
  
4
Thermal Conductivity
23.00 W/m·K
  
99+
35.90 W/m·K
  
36
Critical Temperature
Not Available
  
Thermal Expansion
5.90 µm/(m·K)
  
99+
97.00 µm/(m·K)
  
1
Enthalpy
  
  
Enthalpy of Vaporization
661.10 kJ/mol
  
5
65.90 kJ/mol
  
99+
Enthalpy of Fusion
25.10 kJ/mol
  
8
2.10 kJ/mol
  
99+
Enthalpy of Atomization
703.00 kJ/mol
  
5
78.20 kJ/mol
  
99+
Standard Molar Entropy
43.60 J/mol.K
  
34
85.20 J/mol.K
  
3