Symbol
Tl
  
Tb
  
Group Number
Not Available
  
Period Number
6
  
6
  
Block
p block
  
f block
  
Element Family
Post-Transition
  
Lanthanide
  
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.
  
- At times Terbium metal acts same as Calcium.
- Terbium metal closely similar to Lanthanum metal.
  
Sources
Found As a By-product, Ores of metals, Ores of Minerals
  
Found in Minerals, Found with Other Rare Earth Metals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
William Crookes
  
Carl Gustaf Mosander
  
Discovery
In 1861
  
In 1842
  
Abundance
  
  
Abundance In Sun
~0.0000001 %
  
26
~0.00000001 %
  
29
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.
  
- Terbium salts are used in optical devices like laser devices.
-
Terbium’s alloy lengthens and shortens the magnetic field and this effect forms loudspeaker.
  
Industrial Uses
Chemical Industry
  
Electronic Industry
  
Medical Uses
Medical Research
  
NA
  
Other Uses
Alloys
  
Alloys
  
Biological Properties
  
  
Toxicity
Highly Toxic
  
Low 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
  
Melting Point
1,356.00 °C
  
33
Boiling Point
1,457.00 °C
  
99+
3,123.00 °C
  
29
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Silvery White
  
Luster
NA
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
Vickers Hardness
Not Available
  
Speed of Sound
818.00 m/s
  
99+
2,620.00 m/s
  
35
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
  
Tb
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Not Available
  
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Not Available
  
Ionization Energies
  
  
1st Energy Level
589.40 kJ/mol
  
99+
603.40 kJ/mol
  
99+
2nd Energy Level
1,971.00 kJ/mol
  
14
1,174.80 kJ/mol
  
99+
3rd Energy Level
2,878.00 kJ/mol
  
32
2,417.00 kJ/mol
  
99+
4th Energy Level
Not Available
  
4,203.00 kJ/mol
  
31
Electrochemical Equivalent
7.63 g/amp-hr
  
2
1.98 g/amp-hr
  
31
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Xe] 4f14 5d10 6s2 6p1
  
[Xe] 4f9 6s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Hexagonal Close Packed (HCP)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
HCP-Crystal-Structure-of-Terbium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
158.93 amu
  
99+
Atomic Volume
17.20 cm3/mol
  
31
19.20 cm3/mol
  
22
Adjacent Atomic Numbers
  
  
Valence Electron Potential
9.60 (-eV)
  
99+
46.80 (-eV)
  
33
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
8.23 g/cm3
  
99+
Density When Liquid (at m.p.)
11.22 g/cm3
  
13
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Ductile, Sectile
  
Ductile, Malleable
  
Magnetic Characteristics
  
  
Magnetic Ordering
Diamagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Electrical Conductivity
0.06 106/cm Ω
  
32
0.01 106/cm Ω
  
99+
Electron Affinity
19.20 kJ/mol
  
32
50.00 kJ/mol
  
21
Specific Heat
0.13 J/(kg K)
  
39
0.18 J/(kg K)
  
33
Molar Heat Capacity
26.32 J/mol·K
  
29
28.91 J/mol·K
  
9
Thermal Conductivity
46.10 W/m·K
  
33
11.10 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
29.90 µm/(m·K)
  
12
10.30 µm/(m·K)
  
38
Enthalpy
  
  
Enthalpy of Vaporization
162.10 kJ/mol
  
99+
330.90 kJ/mol
  
26
Enthalpy of Fusion
4.27 kJ/mol
  
99+
10.80 kJ/mol
  
34
Enthalpy of Atomization
179.90 kJ/mol
  
99+
314.00 kJ/mol
  
33
Standard Molar Entropy
64.20 J/mol.K
  
19
73.20 J/mol.K
  
10