Curium Hafnium Comparison
Periodic Table
Symbol
Cm
Hf
Group Number
Not Available
4
14
Period Number
7
6
Block
f block
d block
Element Family
Actinide
Transition Metal
CAS Number
7440519
36
7440586
30
Space Group Name
Not Available
P63/mmc
Space Group Number
Not Available
194.00
5
Facts
Interesting Facts
- Curium metal does not occur free in nature.
- Curium metal is a synthetically produced metal.
- Hafnium metal is highly reactive, hence not found free in nature.
- Hafnium metal as predicated after Mendeleev finished his periodic table.
Sources
Bombarding Plutonium with Helium Ions
By-product Zirconium Refining
History
Who Discovered
Glenn T. Seaborg, Ralph A. James, 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
- Curium metal is used to provide power to electrical equipment for space missions.
- 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
Research Purposes
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes
Biological Properties
Toxicity
Unknown
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
1,340.00 °C
34
2,150.00 °C
10
Boiling Point
3,110.00 °C
30
5,400.00 °C
5
Appearance
Physical State
Solid
Solid
Color
Silver
Gray
Luster
Metallic
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
Cm
Hf
Isotopes
Known Isotopes
15
24
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
581.00 kJ/mol
99+
658.50 kJ/mol
40
2nd Energy Level
1,196.00 kJ/mol
99+
1,440.00 kJ/mol
99+
3rd Energy Level
2,026.00 kJ/mol
99+
2,250.00 kJ/mol
99+
4th Energy Level
3,550.00 kJ/mol
99+
3,216.00 kJ/mol
99+
Electrochemical Equivalent
3.07 g/amp-hr
16
1.66 g/amp-hr
99+
Electron Work Function
Not Available
3.90 eV
27
Other Chemical Properties
Ionization, Radioactive Isotopes
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
96
22
72
99+
Electron Configuration
[Rn] 5f7 6d1 7s2
[Xe] 4f14 5d2 6s2
Crystal Structure
Double Hexagonal Close Packed (DHCP)
Hexagonal Close Packed (HCP)
Crystal Lattice
DHCP-Crystal-Structure-of-Curium.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
96
22
72
99+
Number of Neutrons
151
10
106
29
Number of Electrons
96
22
72
99+
Radius of an Atom
Atomic Radius
174.00 pm
20
159.00 pm
28
Covalent Radius
169.00 pm
26
175.00 pm
23
Van der Waals Radius
200.00 pm
28
200.00 pm
28
Atomic Weight
247.00 amu
18
178.49 amu
39
Atomic Volume
18.28 cm3/mol
26
13.60 cm3/mol
38
Adjacent Atomic Numbers
Valence Electron Potential
44.50 (-eV)
38
81.00 (-eV)
16
Lattice Constant
Not Available
319.64 pm
99+
Lattice Angles
NA
π/2, π/2, 2 π/3
Lattice C/A Ratio
Not Available
1.58
12
Mechanical Properties
Density
Density At Room Temperature
13.51 g/cm3
25
13.31 g/cm3
26
Density When Liquid (at m.p.)
13.85 g/cm3
10
12.00 g/cm3
12
Tensile Strength
Not Available
445.00 MPa
8
Viscosity
Not Available
Not Available
Vapor Pressure
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
Unknown
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
13.51
17
13.31
18
Magnetic Ordering
Antiferromagnetic
Paramagnetic
Electrical Properties
Electrical Property
Unknown
Conductor
Resistivity
1.25 nΩ·m
99+
331.00 nΩ·m
14
Electrical Conductivity
Not Available
0.03 106/cm Ω
39
Electron Affinity
Not Available
0.00 kJ/mol
40
Thermal Properties
Specific Heat
Not Available
0.14 J/(kg K)
37
Molar Heat Capacity
Not Available
25.73 J/mol·K
36
Thermal Conductivity
Not Available
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
15.00 kJ/mol
21
25.10 kJ/mol
8
Enthalpy of Atomization
Not Available
703.00 kJ/mol
5
Standard Molar Entropy
Not Available
43.60 J/mol.K
34
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