Thallium Hafnium Comparison
Periodic Table
Symbol
Tl
Hf
Group Number
13
5
4
14
Period Number
6
6
Block
p block
d block
Element Family
Post-Transition
Transition Metal
CAS Number
7440280
99+
7440586
30
Space Group Name
P63/mmc
P63/mmc
Space Group Number
194.00
5
194.00
5
Facts
Interesting Facts
- Compounds of Thallium metal are highly Toxic.
- Thallium metal is being suspected as a human carcinogen.
- Hafnium metal is highly reactive, hence not found free in nature.
- Hafnium metal as predicated after Mendeleev finished his periodic table.
Sources
Found As a By-product, Ores of metals, Ores of Minerals
By-product Zirconium Refining
History
Who Discovered
William Crookes
Dirk Coster and George de Hevesy
Discovery
In 1861
In 1922
Abundance
Abundance In Universe
5 * 10-9 %
32
7 * 10-8 %
25
Abundance In Sun
~0.0000001 %
26
~0.0000001 %
26
Abundance In Meteorites
0.00 %
99+
0.00 %
37
Abundance In Earth's Crust
0.00 %
99+
0.00 %
31
Abundance In Oceans
0.00 %
34
0.00 %
27
Uses
Uses & Benefits
- Thallium is a toxic metal and hence it has limited uses. Thallium metal is mostly used for producing photoelectric cells.
- In thermometer’s mercury alloy has 8% of thallium, as it has a melting point lower than 20°C.
- 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
Chemical Industry
Ammunition Industry
Medical Uses
Medical Research
NA
Other Uses
Alloys
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes
Biological Properties
Toxicity
Highly Toxic
Toxic
Present in Human Body
Yes
No
In Blood
0.00 Blood/mg dm-3
34
Not Available
In Bone
0.00 p.p.m.
33
Not Available
Physical Properties
Melting Point
303.50 °C
99+
2,150.00 °C
10
Boiling Point
1,457.00 °C
99+
5,400.00 °C
5
Appearance
Physical State
Solid
Solid
Color
Silvery White
Gray
Luster
NA
Metallic
Hardness
Mohs Hardness
1.20
20
5.50
7
Brinell Hardness
26.50 MPa
99+
1,450.00 MPa
6
Vickers Hardness
Not Available
1,520.00 MPa
5
Speed of Sound
818.00 m/s
99+
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
Tl
Hf
Isotopes
Known Isotopes
32
7
32
7
Electronegativity
Pauling Electronegativity
1.62
21
1.30
32
Sanderson Electronegativity
2.25
5
Not Available
Allred Rochow Electronegativity
1.44
17
1.23
25
Mulliken-Jaffe Electronegativity
1.96
6
Not Available
Allen Electronegativity
1.79
13
1.16
37
Electropositivity
Pauling Electropositivity
2.38
33
2.70
22
Ionization Energies
1st Energy Level
589.40 kJ/mol
99+
658.50 kJ/mol
40
2nd Energy Level
1,971.00 kJ/mol
14
1,440.00 kJ/mol
99+
3rd Energy Level
2,878.00 kJ/mol
32
2,250.00 kJ/mol
99+
4th Energy Level
Not Available
3,216.00 kJ/mol
99+
Electrochemical Equivalent
7.63 g/amp-hr
2
1.66 g/amp-hr
99+
Electron Work Function
3.84 eV
28
3.90 eV
27
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Solubility
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
81
35
72
99+
Electron Configuration
[Xe] 4f14 5d10 6s2 6p1
[Xe] 4f14 5d2 6s2
Crystal Structure
Hexagonal Close Packed (HCP)
Hexagonal Close Packed (HCP)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
81
35
72
99+
Number of Neutrons
123
20
106
29
Number of Electrons
81
35
72
99+
Radius of an Atom
Atomic Radius
170.00 pm
22
159.00 pm
28
Covalent Radius
145.00 pm
39
175.00 pm
23
Van der Waals Radius
196.00 pm
30
200.00 pm
28
Atomic Weight
204.38 amu
31
178.49 amu
39
Atomic Volume
17.20 cm3/mol
31
13.60 cm3/mol
38
Adjacent Atomic Numbers
Valence Electron Potential
9.60 (-eV)
99+
81.00 (-eV)
16
Lattice Constant
345.66 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
1.60
6
1.58
12
Mechanical Properties
Density
Density At Room Temperature
11.85 g/cm3
31
13.31 g/cm3
26
Density When Liquid (at m.p.)
11.22 g/cm3
13
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
16.90 (Pa)
5
Not Available
Vapor Pressure at 2000 K
Not Available
0.00 (Pa)
24
Elasticity properties
Shear Modulus
2.80 GPa
99+
30.00 GPa
23
Bulk Modulus
43.00 GPa
28
110.00 GPa
15
Young's Modulus
8.00 GPa
99+
78.00 GPa
25
Poisson Ratio
0.45
2
0.37
7
Other Mechanical Properties
Ductile, Sectile
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
11.85
22
13.31
18
Magnetic Ordering
Diamagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
0.18 nΩ·m
99+
331.00 nΩ·m
14
Electrical Conductivity
0.06 106/cm Ω
32
0.03 106/cm Ω
39
Electron Affinity
19.20 kJ/mol
32
0.00 kJ/mol
40
Thermal Properties
Specific Heat
0.13 J/(kg K)
39
0.14 J/(kg K)
37
Molar Heat Capacity
26.32 J/mol·K
29
25.73 J/mol·K
36
Thermal Conductivity
46.10 W/m·K
33
23.00 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
29.90 µm/(m·K)
12
5.90 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
162.10 kJ/mol
99+
661.10 kJ/mol
5
Enthalpy of Fusion
4.27 kJ/mol
99+
25.10 kJ/mol
8
Enthalpy of Atomization
179.90 kJ/mol
99+
703.00 kJ/mol
5
Standard Molar Entropy
64.20 J/mol.K
19
43.60 J/mol.K
34
|
||
|
||
|
