Symbol
Tl
  
Sc
  
Period Number
6
  
4
  
Block
p block
  
d block
  
Element Family
Post-Transition
  
Transition Metal
  
Space Group Name
P63/mmc
  
P63/mmc
  
Interesting Facts
- Compounds of Thallium metal are highly Toxic.
- Thallium metal is being suspected as a human carcinogen.
  
- Scandium is known as one of the rare earth elements.
- Scandium metal found in rare minerals called Wolframite .
  
Sources
Found As a By-product, Ores of metals, Ores of Minerals
  
Found in Minerals, Mining, Ores of metals, Ores of Minerals
  
History
  
  
Who Discovered
William Crookes
  
Lars Fredrik Nilson
  
Discovery
In 1861
  
In 1879
  
Abundance
  
  
Abundance In Sun
~0.0000001 %
  
26
~0.000004 %
  
16
Abundance In Earth's Crust
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.
  
- Uses of Scandium are limited to research purpose only. However, it has very low density and higher melting point.
-
Its compounds like scandium iodide is used in mercury vapor lamps to produce very bright white light.
  
Industrial Uses
Chemical Industry
  
Electrical Industry, Electronic Industry
  
Medical Uses
Medical Research
  
NA
  
Other Uses
Alloys
  
Alloys
  
Biological Properties
  
  
Toxicity
Highly Toxic
  
Non Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
0.00 Blood/mg dm-3
  
34
0.01 Blood/mg dm-3
  
22
In Bone
0.00 p.p.m.
  
33
0.00 p.p.m.
  
34
Melting Point
1,539.00 °C
  
24
Boiling Point
1,457.00 °C
  
99+
2,832.00 °C
  
35
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Silvery White
  
Luster
NA
  
Lustrous
  
Hardness
  
  
Mohs Hardness
Not Available
  
Speed of Sound
818.00 m/s
  
99+
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 Formula
Tl
  
Sc
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
589.40 kJ/mol
  
99+
633.10 kJ/mol
  
99+
2nd Energy Level
1,971.00 kJ/mol
  
14
1,235.00 kJ/mol
  
99+
3rd Energy Level
2,878.00 kJ/mol
  
32
2,388.60 kJ/mol
  
99+
4th Energy Level
Not Available
  
7,090.60 kJ/mol
  
6
5th Energy Level
Not Available
  
8,843.00 kJ/mol
  
6
6th Energy Level
Not Available
  
10,679.00 kJ/mol
  
7
7th Energy level
Not Available
  
13,310.00 kJ/mol
  
8
8th Energy Level
Not Available
  
15,250.00 kJ/mol
  
11
9th Energy Level
Not Available
  
17,370.00 kJ/mol
  
14
10th Energy Level
Not Available
  
21,726.00 kJ/mol
  
13
11th Energy Level
Not Available
  
24,102.00 kJ/mol
  
16
12th Energy Level
Not Available
  
66,320.00 kJ/mol
  
2
13th Energy Level
Not Available
  
73,010.00 kJ/mol
  
2
14th Energy Level
Not Available
  
80,160.00 kJ/mol
  
3
15th Energy Level
Not Available
  
89,490.00 kJ/mol
  
4
16th Energy Level
Not Available
  
97,400.00 kJ/mol
  
5
17th Energy Level
Not Available
  
105,600.00 kJ/mol
  
6
18th Energy Level
Not Available
  
117,000.00 kJ/mol
  
7
19th Energy Level
Not Available
  
124,270.00 kJ/mol
  
8
Electrochemical Equivalent
7.63 g/amp-hr
  
2
0.56 g/amp-hr
  
99+
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Corrosion, Flammable, Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Xe] 4f14 5d10 6s2 6p1
  
[Ar] 3d1 4s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Hexagonal Close Packed (HCP)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
HCP-Crystal-Structure-of-Scandium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
17.20 cm3/mol
  
31
15.00 cm3/mol
  
34
Adjacent Atomic Numbers
  
  
Valence Electron Potential
9.60 (-eV)
  
99+
58.00 (-eV)
  
24
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, 2 π/3
  
Density
  
  
Density At Room Temperature
11.85 g/cm3
  
31
2.99 g/cm3
  
99+
Density When Liquid (at m.p.)
11.22 g/cm3
  
13
2.80 g/cm3
  
99+
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Ductile, Sectile
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Diamagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
562.00 nΩ·m
  
10
Electrical Conductivity
0.06 106/cm Ω
  
32
0.02 106/cm Ω
  
99+
Electron Affinity
19.20 kJ/mol
  
32
18.10 kJ/mol
  
33
Specific Heat
0.13 J/(kg K)
  
39
0.60 J/(kg K)
  
8
Molar Heat Capacity
26.32 J/mol·K
  
29
25.52 J/mol·K
  
37
Thermal Conductivity
46.10 W/m·K
  
33
15.80 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
29.90 µm/(m·K)
  
12
10.20 µm/(m·K)
  
39
Enthalpy
  
  
Enthalpy of Vaporization
162.10 kJ/mol
  
99+
314.20 kJ/mol
  
28
Enthalpy of Fusion
4.27 kJ/mol
  
99+
14.10 kJ/mol
  
25
Enthalpy of Atomization
179.90 kJ/mol
  
99+
343.00 kJ/mol
  
28
Standard Molar Entropy
64.20 J/mol.K
  
19
34.60 J/mol.K
  
99+