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Hafnium vs Actinium


Actinium vs Hafnium


Periodic Table

Symbol
Hf   
Ac   

Group Number
4   
14
Not Available   

Period Number
6   
7   

Block
d block   
f block   

Element Family
Transition Metal   
Actinide   

CAS Number
7440586   
30
7440348   
99+

Space Group Name
P63/mmc   
Fm_ 3m   

Space Group Number
194.00   
5
225.00   
2

Facts

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   
Obtained by Treating Radium with Neutrons, Ores of metals   

History
  
  

Who Discovered
Dirk Coster and George de Hevesy   
Friedrich Oskar Giesel   

Discovery
In 1922   
In 1902   

Abundance
  
  

Abundance In Universe
7 * 10-8 %   
25
Not Available   

Abundance In Sun
~0.0000001 %   
26
~-9999 %   

Abundance In Meteorites
0.00 %   
37
Not Available   

Abundance In Earth's Crust
0.00 %   
31
Not Available   

Abundance In Oceans
0.00 %   
27
Not Available   

Uses

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.
  
  • Actinium metal has a great source of alpha rays but it is hardly used outside research purpose.
  

Industrial Uses
Ammunition Industry   
NA   

Medical Uses
NA   
NA   

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

Biological Properties
  
  

Toxicity
Toxic   
Toxic   

Present in Human Body
No   
No   

In Blood
Not Available   
0.00 Blood/mg dm-3   
37

In Bone
Not Available   
0.00 p.p.m.   
36

Physical Properties

Melting Point
2,150.00 °C   
10
1,227.00 °C   
38

Boiling Point
5,400.00 °C   
5
3,200.00 °C   
26

Appearance
  
  

Physical State
Solid   
Solid   

Color
Gray   
Silvery White   

Luster
Metallic   
NA   

Hardness
  
  

Mohs Hardness
5.50   
7
Not Available   

Brinell Hardness
1,450.00 MPa   
6
Not Available   

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 Properties

Chemical Formula
Hf   
Ac   

Isotopes
  
  

Known Isotopes
32   
7
29   
10

Electronegativity
  
  

Pauling Electronegativity
1.30   
32
1.10   
99+

Allred Rochow Electronegativity
1.23   
25
1.00   
36

Allen Electronegativity
1.16   
37
Not Available   

Electropositivity
  
  

Pauling Electropositivity
2.70   
22
2.90   
10

Ionization Energies
  
  

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

2nd Energy Level
1,440.00 kJ/mol   
99+
1,170.00 kJ/mol   
99+

3rd Energy Level
2,250.00 kJ/mol   
99+
1,900.00 kJ/mol   
99+

4th Energy Level
3,216.00 kJ/mol   
99+
4,700.00 kJ/mol   
23

Electrochemical Equivalent
1.66 g/amp-hr   
99+
2.82 g/amp-hr   
18

Electron Work Function
3.90 eV   
27
Not Available   

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

Atomic Properties

Atomic Number
72   
99+
89   
29

Electron Configuration
[Xe] 4f14 5d2 6s2   
[Rn] 6d1 7s2   

Crystal Structure
Hexagonal Close Packed (HCP)   
Face Centered Cubic (FCC)   

Crystal Lattice
BCC-Crystal-Structure-.jpg#100   
FCC-Crystal-Structure-of-Actinium.jpg#100   

Atom
  
  

Number of Protons
72   
99+
89   
29

Number of Neutrons
106   
29
138   
16

Number of Electrons
72   
99+
89   
29

Radius of an Atom
  
  

Atomic Radius
159.00 pm   
28
195.00 pm   
7

Covalent Radius
175.00 pm   
23
Not Available   

Van der Waals Radius
200.00 pm   
28
Not Available   

Atomic Weight
178.49 amu   
39
227.00 amu   
25

Atomic Volume
13.60 cm3/mol   
38
22.54 cm3/mol   
11

Adjacent Atomic Numbers
  
  

Previous Element
Lutetium
  
Radium
  

Next Element
Tantalum
  
Thorium
  

Valence Electron Potential
81.00 (-eV)   
16
38.60 (-eV)   
99+

Lattice Constant
319.64 pm   
99+
567.00 pm   
8

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

Lattice C/A Ratio
1.58   
12
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
13.31 g/cm3   
26
10.00 g/cm3   
37

Density When Liquid (at m.p.)
12.00 g/cm3   
12
Not Available   

Tensile Strength
445.00 MPa   
8
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

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

Elasticity properties
  
  

Shear Modulus
30.00 GPa   
23
Not Available   

Bulk Modulus
110.00 GPa   
15
Not Available   

Young's Modulus
78.00 GPa   
25
Not Available   

Poisson Ratio
0.37   
7
Not Available   

Other Mechanical Properties
Ductile, Malleable   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
13.31   
18
10.07   
28

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Unknown   

Resistivity
331.00 nΩ·m   
14
Not Available   

Electrical Conductivity
0.03 106/cm Ω   
39
Not Available   

Electron Affinity
0.00 kJ/mol   
40
Not Available   

Thermal Properties

Specific Heat
0.14 J/(kg K)   
37
0.12 J/(kg K)   
40

Molar Heat Capacity
25.73 J/mol·K   
36
27.20 J/mol·K   
18

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
5.90 µm/(m·K)   
99+
Not Available   

Enthalpy
  
  

Enthalpy of Vaporization
661.10 kJ/mol   
5
Not Available   

Enthalpy of Fusion
25.10 kJ/mol   
8
Not Available   

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

Standard Molar Entropy
43.60 J/mol.K   
34
56.50 J/mol.K   
25

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