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Americium vs Hafnium


Hafnium vs Americium


Periodic Table

Symbol
Am   
Hf   

Group Number
Not Available   
4   
14

Period Number
7   
6   

Block
f block   
d block   

Element Family
Actinide   
Transition Metal   

CAS Number
7440359   
99+
7440586   
30

Space Group Name
P63/mmc   
P63/mmc   

Space Group Number
194.00   
5
194.00   
5

Facts

Interesting Facts
  • Americium metal is produced by bombarding Plutonium with Neutrons.
  • Americium metal was discovered as a by-product while testing an atomic bomb (Manhattan Project).
  
  • Hafnium metal is highly reactive, hence not found free in nature.
  • Hafnium metal as predicated after Mendeleev finished his periodic table.
  

Sources
Obtained By Bombarding Plutonium with Neutrons   
By-product Zirconium Refining   

History
  
  

Who Discovered
Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso   
Dirk Coster and George de Hevesy   

Discovery
In 1944   
In 1922   

Abundance
  
  

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

Abundance In Sun
~-9999 %   
~0.0000001 %   
26

Abundance In Meteorites
Not Available   
0.00 %   
37

Abundance In Earth's Crust
Not Available   
0.00 %   
31

Abundance In Oceans
Not Available   
0.00 %   
27

Uses

Uses & Benefits
  • Americium metal is used in smoke detection alarms.
  • In the future, this metal has a potential to be used in batteries of spacecrafts.
  
  • 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, Research Purposes   
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes   

Biological Properties
  
  

Toxicity
Toxic   
Toxic   

Present in Human Body
No   
No   

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

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

Physical Properties

Melting Point
994.00 °C   
99+
2,150.00 °C   
10

Boiling Point
2,607.00 °C   
99+
5,400.00 °C   
5

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Gray   

Luster
NA   
Metallic   

Hardness
  
  

Mohs Hardness
Not Available   
5.50   
7

Brinell Hardness
Not Available   
1,450.00 MPa   
6

Vickers Hardness
Not Available   
1,520.00 MPa   
5

Speed of Sound
Not Available   
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
Am   
Hf   

Isotopes
  
  

Known Isotopes
16   
23
32   
7

Electronegativity
  
  

Pauling Electronegativity
1.30   
32
1.30   
32

Allred Rochow Electronegativity
1.20   
27
1.23   
25

Allen Electronegativity
Not Available   
1.16   
37

Electropositivity
  
  

Pauling Electropositivity
2.70   
22
2.70   
22

Ionization Energies
  
  

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

2nd Energy Level
1,158.00 kJ/mol   
99+
1,440.00 kJ/mol   
99+

3rd Energy Level
2,132.00 kJ/mol   
99+
2,250.00 kJ/mol   
99+

4th Energy Level
3,493.00 kJ/mol   
99+
3,216.00 kJ/mol   
99+

Electrochemical Equivalent
3.02 g/amp-hr   
17
1.66 g/amp-hr   
99+

Electron Work Function
Not Available   
3.90 eV   
27

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

Atomic Properties

Atomic Number
95   
23
72   
99+

Electron Configuration
[Rn] 5f7 7s2   
[Xe] 4f14 5d2 6s2   

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

Crystal Lattice
DHCP-Crystal-Structure-of-Americium.jpg#100   
BCC-Crystal-Structure-.jpg#100   

Atom
  
  

Number of Protons
95   
23
72   
99+

Number of Neutrons
148   
12
106   
29

Number of Electrons
95   
23
72   
99+

Radius of an Atom
  
  

Atomic Radius
173.00 pm   
21
159.00 pm   
28

Covalent Radius
180.00 pm   
21
175.00 pm   
23

Van der Waals Radius
244.00 pm   
10
200.00 pm   
28

Atomic Weight
243.00 amu   
20
178.49 amu   
39

Atomic Volume
17.86 cm3/mol   
29
13.60 cm3/mol   
38

Adjacent Atomic Numbers
  
  

Previous Element
Plutonium
  
Lutetium
  

Next Element
Curium
  
Tantalum
  

Valence Electron Potential
44.00 (-eV)   
40
81.00 (-eV)   
16

Lattice Constant
346.81 pm   
99+
319.64 pm   
99+

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

Lattice C/A Ratio
Not Available   
1.58   
12

Mechanical Properties

Density
  
  

Density At Room Temperature
12.00 g/cm3   
30
13.31 g/cm3   
26

Density When Liquid (at m.p.)
Not Available   
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)   
13
Not Available   

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

Elasticity properties
  
  

Shear Modulus
Not Available   
30.00 GPa   
23

Bulk Modulus
Not Available   
110.00 GPa   
15

Young's Modulus
Not Available   
78.00 GPa   
25

Poisson Ratio
Not Available   
0.37   
7

Other Mechanical Properties
NA   
Ductile, Malleable   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
13.67   
15
13.31   
18

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Unknown   
Conductor   

Resistivity
0.69 nΩ·m   
99+
331.00 nΩ·m   
14

Electrical Conductivity
0.02 106/cm Ω   
99+
0.03 106/cm Ω   
39

Electron Affinity
Not Available   
0.00 kJ/mol   
40

Thermal Properties

Specific Heat
0.11 J/(kg K)   
99+
0.14 J/(kg K)   
37

Molar Heat Capacity
62.70 J/mol·K   
1
25.73 J/mol·K   
36

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

Critical Temperature
Not Available   
Not Available   

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

Enthalpy
  
  

Enthalpy of Vaporization
Not Available   
661.10 kJ/mol   
5

Enthalpy of Fusion
14.39 kJ/mol   
24
25.10 kJ/mol   
8

Enthalpy of Atomization
268.00 kJ/mol   
40
703.00 kJ/mol   
5

Standard Molar Entropy
Not Available   
43.60 J/mol.K   
34

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