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Holmium Hafnium Comparison


Hafnium Holmium comparison


Periodic Table

Symbol
Ho   
Hf   

Group Number
Not Available   
4   
14

Period Number
6   
6   

Block
f block   
d block   

Element Family
Lanthanide   
Transition Metal   

CAS Number
7440600   
29
7440586   
30

Space Group Name
P63/mmc   
P63/mmc   

Space Group Number
194.00   
5
194.00   
5

Facts

Interesting Facts
  • Holmium metal is very soft and malleable.
  • Holmium metal is well known for its corrosion resistivity.
  
  • Hafnium metal is highly reactive, hence not found free in nature.
  • Hafnium metal as predicated after Mendeleev finished his periodic table.
  

Sources
Found in Minerals, Mining, Ores of Minerals   
By-product Zirconium Refining   

History
  
  

Who Discovered
Marc Delafontaine   
Dirk Coster and George de Hevesy   

Discovery
In 1878   
In 1922   

Abundance
  
  

Abundance In Universe
5 * 10-8 %   
27
7 * 10-8 %   
25

Abundance In Sun
~-9999 %   
~0.0000001 %   
26

Abundance In Meteorites
0.00 %   
99+
0.00 %   
37

Abundance In Earth's Crust
0.00 %   
38
0.00 %   
31

Abundance In Oceans
0.00 %   
99+
0.00 %   
27

Uses

Uses & Benefits
  • Holmium metal has an ability to absorb neutrons, so this metal is used in nuclear reactors to keep the chain reactions of elements under control.
  • Alloys of Holmium are used to produce Magnet.
  
  • 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.
  

Industrial Uses
NA   
Ammunition Industry   

Medical Uses
NA   
NA   

Other Uses
Alloys, Nuclear Research   
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes   

Biological Properties
  
  

Toxicity
Low Toxic   
Toxic   

Present in Human Body
No   
No   

Physical Properties

Melting Point
1,461.00 °C   
30
2,150.00 °C   
10

Boiling Point
2,600.00 °C   
99+
5,400.00 °C   
5

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Gray   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
Not Available   
5.50   
7

Brinell Hardness
746.00 MPa   
13
1,450.00 MPa   
6

Vickers Hardness
481.00 MPa   
23
1,520.00 MPa   
5

Speed of Sound
2,760.00 m/s   
30
3,010.00 m/s   
27

Optical Properties
  
  

Allotropes
No   
No   

α Allotropes
Not Available   
Not Available   

β Allotropes
Not Available   
Not Available   

γ Allotropes
Not Available   
Not Available   

Chemical Properties

Chemical Formula
Ho   
Hf   

Isotopes
  
  

Known Isotopes
34   
5
32   
7

Electronegativity
  
  

Pauling Electronegativity
1.23   
37
1.30   
32

Allred Rochow Electronegativity
1.10   
30
1.23   
25

Allen Electronegativity
Not Available   
1.16   
37

Electropositivity
  
  

Pauling Electropositivity
2.77   
17
2.70   
22

Ionization Energies
  
  

1st Energy Level
581.00 kJ/mol   
99+
658.50 kJ/mol   
40

2nd Energy Level
1,140.00 kJ/mol   
99+
1,440.00 kJ/mol   
99+

3rd Energy Level
2,204.00 kJ/mol   
99+
2,250.00 kJ/mol   
99+

4th Energy Level
4,100.00 kJ/mol   
34
3,216.00 kJ/mol   
99+

Electrochemical Equivalent
2.02 g/amp-hr   
29
1.66 g/amp-hr   
99+

Electron Work Function
Not Available   
3.90 eV   
27

Other Chemical Properties
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility   
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility   

Atomic Properties

Atomic Number
67   
99+
72   
99+

Electron Configuration
[Xe] 4f11 6s2   
[Xe] 4f14 5d2 6s2   

Crystal Structure
Hexagonal Close Packed (HCP)   
Hexagonal Close Packed (HCP)   

Crystal Lattice
HCP-Crystal-Structure-of-Holmium.jpg#100   
BCC-Crystal-Structure-.jpg#100   

Atom
  
  

Number of Protons
67   
99+
72   
99+

Number of Neutrons
98   
34
106   
29

Number of Electrons
67   
99+
72   
99+

Radius of an Atom
  
  

Atomic Radius
176.00 pm   
18
159.00 pm   
28

Covalent Radius
192.00 pm   
17
175.00 pm   
23

Van der Waals Radius
216.00 pm   
24
200.00 pm   
28

Atomic Weight
164.93 amu   
99+
178.49 amu   
39

Atomic Volume
18.70 cm3/mol   
24
13.60 cm3/mol   
38

Adjacent Atomic Numbers
  
  

Previous Element
Dysprosium
  
Lutetium
  

Next Element
Erbium
  
Tantalum
  

Valence Electron Potential
47.90 (-eV)   
31
81.00 (-eV)   
16

Lattice Constant
357.73 pm   
38
319.64 pm   
99+

Lattice Angles
π/2, π/2, 2 π/3   
π/2, π/2, 2 π/3   

Lattice C/A Ratio
1.57   
17
1.58   
12

Mechanical Properties

Density
  
  

Density At Room Temperature
8.79 g/cm3   
99+
13.31 g/cm3   
26

Density When Liquid (at m.p.)
8.34 g/cm3   
26
12.00 g/cm3   
12

Tensile Strength
Not Available   
445.00 MPa   
8

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)   
16
Not Available   

Vapor Pressure at 2000 K
Not Available   
0.00 (Pa)   
24

Elasticity properties
  
  

Shear Modulus
26.30 GPa   
28
30.00 GPa   
23

Bulk Modulus
40.20 GPa   
32
110.00 GPa   
15

Young's Modulus
64.80 GPa   
31
78.00 GPa   
25

Poisson Ratio
0.23   
29
0.37   
7

Other Mechanical Properties
Ductile, Malleable, Sectile   
Ductile, Malleable   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
8.80   
35
13.31   
18

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
814.00 nΩ·m   
4
331.00 nΩ·m   
14

Electrical Conductivity
0.01 106/cm Ω   
99+
0.03 106/cm Ω   
39

Electron Affinity
50.00 kJ/mol   
21
0.00 kJ/mol   
40

Thermal Properties

Specific Heat
0.16 J/(kg K)   
35
0.14 J/(kg K)   
37

Molar Heat Capacity
27.15 J/mol·K   
19
25.73 J/mol·K   
36

Thermal Conductivity
16.20 W/m·K   
99+
23.00 W/m·K   
99+

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
11.20 µm/(m·K)   
35
5.90 µm/(m·K)   
99+

Enthalpy
  
  

Enthalpy of Vaporization
241.00 kJ/mol   
38
661.10 kJ/mol   
5

Enthalpy of Fusion
11.76 kJ/mol   
29
25.10 kJ/mol   
8

Enthalpy of Atomization
301.00 kJ/mol   
36
703.00 kJ/mol   
5

Standard Molar Entropy
75.30 J/mol.K   
8
43.60 J/mol.K   
34

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