Hafnium Americium Comparison
Periodic Table
Symbol
Hf
Am
Group Number
4
14
Not Available
Period Number
6
7
Block
d block
f block
Element Family
Transition Metal
Actinide
CAS Number
7440586
30
7440359
99+
Space Group Name
P63/mmc
P63/mmc
Space Group Number
194.00
5
194.00
5
Facts
Interesting Facts
- Hafnium metal is highly reactive, hence not found free in nature.
- Hafnium metal as predicated after Mendeleev finished his periodic table.
- Americium metal is produced by bombarding Plutonium with Neutrons.
- Americium metal was discovered as a by-product while testing an atomic bomb (Manhattan Project).
Sources
By-product Zirconium Refining
Obtained By Bombarding Plutonium with Neutrons
History
Who Discovered
Dirk Coster and George de Hevesy
Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso
Discovery
In 1922
In 1944
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.
- Americium metal is used in smoke detection alarms.
- In the future, this metal has a potential to be used in batteries of spacecrafts.
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
994.00 °C
99+
Boiling Point
5,400.00 °C
5
2,607.00 °C
99+
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
Am
Isotopes
Known Isotopes
32
7
16
23
Electronegativity
Pauling Electronegativity
1.30
32
1.30
32
Allred Rochow Electronegativity
1.23
25
1.20
27
Allen Electronegativity
1.16
37
Not Available
Electropositivity
Pauling Electropositivity
2.70
22
2.70
22
Ionization Energies
1st Energy Level
658.50 kJ/mol
40
578.00 kJ/mol
99+
2nd Energy Level
1,440.00 kJ/mol
99+
1,158.00 kJ/mol
99+
3rd Energy Level
2,250.00 kJ/mol
99+
2,132.00 kJ/mol
99+
4th Energy Level
3,216.00 kJ/mol
99+
3,493.00 kJ/mol
99+
Electrochemical Equivalent
1.66 g/amp-hr
99+
3.02 g/amp-hr
17
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+
95
23
Electron Configuration
[Xe] 4f14 5d2 6s2
[Rn] 5f7 7s2
Crystal Structure
Hexagonal Close Packed (HCP)
Double Hexagonal Close Packed (DHCP)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
DHCP-Crystal-Structure-of-Americium.jpg#100
Atom
Number of Protons
72
99+
95
23
Number of Neutrons
106
29
148
12
Number of Electrons
72
99+
95
23
Radius of an Atom
Atomic Radius
159.00 pm
28
173.00 pm
21
Covalent Radius
175.00 pm
23
180.00 pm
21
Van der Waals Radius
200.00 pm
28
244.00 pm
10
Atomic Weight
178.49 amu
39
243.00 amu
20
Atomic Volume
13.60 cm3/mol
38
17.86 cm3/mol
29
Adjacent Atomic Numbers
Valence Electron Potential
81.00 (-eV)
16
44.00 (-eV)
40
Lattice Constant
319.64 pm
99+
346.81 pm
99+
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.58
12
Not Available
Mechanical Properties
Density
Density At Room Temperature
13.31 g/cm3
26
12.00 g/cm3
30
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 1000 K
Not Available
0.00 (Pa)
13
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
13.67
15
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Unknown
Resistivity
331.00 nΩ·m
14
0.69 nΩ·m
99+
Electrical Conductivity
0.03 106/cm Ω
39
0.02 106/cm Ω
99+
Electron Affinity
0.00 kJ/mol
40
Not Available
Thermal Properties
Specific Heat
0.14 J/(kg K)
37
0.11 J/(kg K)
99+
Molar Heat Capacity
25.73 J/mol·K
36
62.70 J/mol·K
1
Thermal Conductivity
23.00 W/m·K
99+
10.00 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
14.39 kJ/mol
24
Enthalpy of Atomization
703.00 kJ/mol
5
268.00 kJ/mol
40
Standard Molar Entropy
43.60 J/mol.K
34
Not Available
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