Hafnium Silver Comparison
Periodic Table
Symbol
Hf
Ag
Group Number
4
14
11
7
Period Number
6
5
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
7440586
30
7440224
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.
- It is the most reflective element.
- Silver is the second most ductile metal after Gold.
- It is also used in Dentistry as a dental alloys for clips and crowning.
Sources
By-product Zirconium Refining
Earth's crust, Found in Minerals, Ores of metals
History
Who Discovered
Dirk Coster and George de Hevesy
Unknown
Discovery
In 1922
Before 5000 BC
Abundance
Abundance In Universe
7 * 10-8 %
25
6 * 10-8 %
26
Abundance In Sun
~0.0000001 %
26
~0.0000001 %
26
Abundance In Meteorites
0.00 %
37
0.00 %
38
Abundance In Earth's Crust
0.00 %
31
0.00 %
99+
Abundance In Oceans
0.00 %
27
0.00 %
19
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.
- Silver is mainly used for Jewelry and show piece.
- It is used for manufacturing high quality mirrors due to its reflectivity property.
Industrial Uses
Ammunition Industry
Chemical Industry, Clothing Industry, Electrical Industry
Medical Uses
NA
Dentistry, Pharmaceutical Industry
Other Uses
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes
Alloys, Bullion, Coinage, Jewellery, Sculptures, Statues
Biological Properties
Toxicity
Toxic
Non Toxic
Present in Human Body
No
Yes
In Blood
Not Available
0.00 Blood/mg dm-3
29
In Bone
Not Available
0.44 p.p.m.
20
Physical Properties
Melting Point
2,150.00 °C
10
961.93 °C
99+
Boiling Point
5,400.00 °C
5
2,212.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Gray
Silvery White
Luster
Metallic
Metallic
Hardness
Mohs Hardness
5.50
7
2.50
14
Brinell Hardness
1,450.00 MPa
6
251.00 MPa
37
Vickers Hardness
1,520.00 MPa
5
229.00 MPa
30
Speed of Sound
3,010.00 m/s
27
2,680.00 m/s
34
Optical Properties
Reflectivity
Not Available
97.00 %
1
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
Ag
Isotopes
Known Isotopes
32
7
36
3
Electronegativity
Pauling Electronegativity
1.30
32
1.93
9
Sanderson Electronegativity
Not Available
1.83
11
Allred Rochow Electronegativity
1.23
25
1.42
18
Mulliken-Jaffe Electronegativity
Not Available
1.47
15
Allen Electronegativity
1.16
37
1.87
7
Electropositivity
Pauling Electropositivity
2.70
22
2.07
99+
Ionization Energies
1st Energy Level
658.50 kJ/mol
40
731.00 kJ/mol
27
2nd Energy Level
1,440.00 kJ/mol
99+
2,070.00 kJ/mol
11
3rd Energy Level
2,250.00 kJ/mol
99+
3,361.00 kJ/mol
19
4th Energy Level
3,216.00 kJ/mol
99+
Not Available
Electrochemical Equivalent
1.66 g/amp-hr
99+
4.02 g/amp-hr
7
Electron Work Function
3.90 eV
27
4.26 eV
20
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Chemical Stability, Ionization, Solubility
Atomic Properties
Atomic Number
72
99+
47
99+
Electron Configuration
[Xe] 4f14 5d2 6s2
[Kr] 4d10 5s1
Crystal Structure
Hexagonal Close Packed (HCP)
Face Centered Cubic (FCC)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
FCC-Crystal-Structure-of-Silver.jpg#100
Atom
Number of Protons
72
99+
47
99+
Number of Neutrons
106
29
61
99+
Number of Electrons
72
99+
47
99+
Radius of an Atom
Atomic Radius
159.00 pm
28
144.00 pm
36
Covalent Radius
175.00 pm
23
145.00 pm
39
Van der Waals Radius
200.00 pm
28
172.00 pm
38
Atomic Weight
178.49 amu
39
107.87 amu
99+
Atomic Volume
13.60 cm3/mol
38
10.30 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
81.00 (-eV)
16
11.40 (-eV)
99+
Lattice Constant
319.64 pm
99+
408.53 pm
20
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
10.49 g/cm3
35
Density When Liquid (at m.p.)
12.00 g/cm3
12
9.32 g/cm3
21
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)
14
Vapor Pressure at 2000 K
0.00 (Pa)
24
Not Available
Elasticity properties
Shear Modulus
30.00 GPa
23
30.00 GPa
23
Bulk Modulus
110.00 GPa
15
100.00 GPa
16
Young's Modulus
78.00 GPa
25
83.00 GPa
23
Poisson Ratio
0.37
7
0.37
7
Other Mechanical Properties
Ductile, Malleable
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
13.31
18
10.50
26
Magnetic Ordering
Paramagnetic
Diamagnetic
Susceptibility
Not Available
0.00
5
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
331.00 nΩ·m
14
15.87 nΩ·m
99+
Electrical Conductivity
0.03 106/cm Ω
39
0.63 106/cm Ω
1
Electron Affinity
0.00 kJ/mol
40
125.60 kJ/mol
5
Thermal Properties
Specific Heat
0.14 J/(kg K)
37
0.24 J/(kg K)
25
Molar Heat Capacity
25.73 J/mol·K
36
25.35 J/mol·K
99+
Thermal Conductivity
23.00 W/m·K
99+
429.00 W/m·K
1
Critical Temperature
Not Available
Not Available
Thermal Expansion
5.90 µm/(m·K)
99+
18.90 µm/(m·K)
23
Enthalpy
Enthalpy of Vaporization
661.10 kJ/mol
5
255.10 kJ/mol
37
Enthalpy of Fusion
25.10 kJ/mol
8
11.30 kJ/mol
31
Enthalpy of Atomization
703.00 kJ/mol
5
284.50 kJ/mol
37
Standard Molar Entropy
43.60 J/mol.K
34
42.60 J/mol.K
35
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