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What is Thallium?

All Metals

Nihonium
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Tennessine
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Thallium In Periodic Table

Symbol
Tl

Group Number
13
5
📊

Period Number
6
📊

Block
p block
📊

Element Family
Post-​Transition
📊

CAS Number
7440280
52

Space Group Name
P63/mmc

Space Group Number
194.00
5
📊

Facts about Thallium

Interesting Facts
  • Compounds of Thallium metal are highly Toxic.
  • Thallium metal is being suspected as a human carcinogen.

Sources
Found As a By-product, Ores of metals, Ores of Minerals

History of Thallium

Who Discovered
William Crookes

Discovery
In 1861

Abundance of Thallium

Abundance In Universe
0.00 %
📊

Abundance In Sun
0.00 %
📊

Abundance In Meteorites
0.00 %
📊

Abundance In Earth's Crust
0.00 %
📊

Abundance In Oceans
0.00 %
📊

Abundance In Humans
Not Available
📊

Uses of Thallium

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.

Industrial Uses
Chemical Industry

Medical Uses
Medical Research

Other Uses
Alloys

Biological Properties

Toxicity
Highly Toxic
📊

Present in Human Body
📊

In Blood
0.00 Blood/mg dm-3

In Bone
0.00 p.p.m.

Physical Properties of Thallium

Melting Point
303.50 °C
69
📊

Boiling Point
1,457.00 °C
60
📊

Appearance of Thallium

Physical State
Solid
📊

Color
Silvery White

Luster
NA
📊

Hardness of Thallium

Mohs Hardness
1.20
📊

Brinell Hardness
26.50 MPa
📊

Vickers Hardness
Not Available
📊

Speed of Sound
818.00 m/s
53
📊

Optical Properties

Refractive Index
Not Available
📊

Reflectivity
Not Available
📊

Allotropes

α Allotropes
Not Available

β Allotropes
Not Available

γ Allotropes
Not Available

Chemical Properties of Thallium

Chemical Formula
Tl

Isotopes of Thallium

Known Isotopes
32
📊

Electronegativity

Pauling Electronegativity
1.62
📊

Sanderson Electronegativity
2.25
📊

Allred Rochow Electronegativity
1.44
📊

Mulliken-Jaffe Electronegativity
1.96
📊

Allen Electronegativity
1.79
📊

Electropositivity

Pauling Electropositivity
2.38
📊

Ionization Energies

1st Energy Level
589.40 kJ/mol
📊

2nd Energy Level
1,971.00 kJ/mol
📊

3rd Energy Level
2,878.00 kJ/mol
📊

4th Energy Level
Not Available
📊

5th Energy Level
Not Available
📊

6th Energy Level
Not Available
📊

7th Energy level
Not Available
📊

8th Energy Level
Not Available
📊

9th Energy Level
Not Available
📊

10th Energy Level
Not Available
📊

11th Energy Level
Not Available

12th Energy Level
Not Available

13th Energy Level
Not Available

14th Energy Level
Not Available

15th Energy Level
Not Available

16th Energy Level
Not Available

17th Energy Level
Not Available

18th Energy Level
Not Available
📊

19th Energy Level
Not Available

20th Energy Level
Not Available

21st Energy Level
Not Available

22nd Energy Level
Not Available

23rd Energy Level
Not Available

24th Energy Level
Not Available

25th Energy Level
Not Available

26th Energy Level
Not Available

27th Energy Level
Not Available

28th Energy Level
Not Available

29th Energy Level
Not Available

30th Energy Level
Not Available

Electrochemical Equivalent
7.63 g/amp-hr
2
📊

Electron Work Function
3.84 eV
28
📊

Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Solubility

Atomic Properties of Thallium

Atomic Number
81
35
📊

Electron Configuration
[Xe] 4f14 5d10 6s2 6p1

Crystal Structure
Hexagonal Close Packed (HCP)
📊

Crystal Lattice
BCC-Crystal-Structure-.jpg#100

Atom of Thallium

Number of Protons
81
📊

Number of Neutrons
123
📊

Number of Electrons
81
📊

Radius of an Atom

Atomic Radius
170.00 pm
📊

Covalent Radius
145.00 pm
📊

Van der Waals Radius
196.00 pm
📊

Atomic Weight
204.38 amu
31
📊

Atomic Volume
17.20 cm3/mol
31
📊

Adjacent Atomic Numbers

Previous Element

Next Element

Valence Electron Potential
9.60 (-eV)
64
📊

Lattice Constant
345.66 pm
45
📊

Lattice Angles
π/2, π/2, 2 π/3

Lattice C/A Ratio
1.60
6
📊

Mechanical Properties of Thallium

Density of Thallium

Density At Room Temperature
11.85 g/cm3
📊

Density When Liquid (at m.p.)
11.22 g/cm3
📊

Tensile Strength
Not Available
📊

Viscosity
Not Available
📊

Vapor Pressure of Thallium

Vapor Pressure at 1000 K
16.90 (Pa)
📊

Vapor Pressure at 2000 K
Not Available
📊

Elasticity properties

Shear Modulus
2.80 GPa
📊

Bulk Modulus
43.00 GPa
📊

Young's Modulus
8.00 GPa
📊

Poisson Ratio
0.45
2
📊

Other Mechanical Properties
Ductile, Sectile

Magnetic Properties of Thallium

Magnetic Characteristics of Thallium

Specific Gravity
11.85
📊

Magnetic Ordering
Diamagnetic
📊

Permeability
Not Available
📊

Susceptibility
Not Available
📊

Electrical Properties

Electrical Property
Conductor
📊

Resistivity
0.18 nΩ·m
📊

Electrical Conductivity
0.06 106/cm Ω
📊

Electron Affinity
19.20 kJ/mol
📊

Thermal Properties of Thallium

Specific Heat
0.13 J/(kg K)
39
📊

Molar Heat Capacity
26.32 J/mol·K
29
📊

Thermal Conductivity
46.10 W/m·K
33
📊

Critical Temperature
Not Available

Thermal Expansion
29.90 µm/(m·K)
12
📊

Enthalpy of Thallium

Enthalpy of Vaporization
162.10 kJ/mol
📊

Enthalpy of Fusion
4.27 kJ/mol
📊

Enthalpy of Atomization
179.90 kJ/mol
📊

Standard Molar Entropy
64.20 J/mol.K
19
📊

Thallium Metal

Metals have been an inseparable component of major civilizations since centuries. Although metals were utilized since time unknown, researchers put considerable efforts in giving them appropriate names and defining their different properties and characteristics. This nomenclature process helped in arranging these metals in a well-organized fashion, known as the periodic table. In this periodic table, Thallium metal is also represented by the symbol Tl. This atomic symbol of Thallium is useful in indicating the position of metal Tl in the periodic table. If you are curious-headed or a science-geek, the common questions about metals are What is Thallium? What are its physical, chemical, mechanical, electrical and thermal properties? Find all the relevant facts about Tl metals in the following sections.

Periodic Table of Thallium

Periodic table of Thallium comments over its position in the periodic table, on the basis of parameters like group number, period row, atomic number and orbital block. The metals which have electrons falling in the same sub-shell are grouped under the same block corresponding to its respective orbital. Thallium metal belongs to Post Transition Metals category of the periodic table. Metals down a group have same valency while metals across a period have the same number of shells. Its group number (column number) is 13, whereas its period number is 6. It is placed under p block of the periodic table & is one of the prominent p block elements.

Thallium Metal Properties

Metals have certain properties by which they can be distinguished from one another. Magnetic and Atomic Structure of Thallium are few widely searched properties. Using the comparison facility, you can not only view the individual metal properties, but also compare the properties of multiple metals to get a thorough comparative analysis between the metals of your choice. Atomic number is a basic building block for the arrangement of metals in the periodic table. Atomic number of Thallium is 81 and its atomic weight is 204.38 amu. The electrons in its atom are arranged in orbitals as [Xe] 4f14 5d10 6s2 6p1. Nuclear particles in Thallium atom are 123 neutrons, 81 protons and 81 electrons.

Physical and Chemical Characteristics of Thallium

Physical and chemical characteristics of Thallium are two major criteria while comparing this metal with other metals. Physical Properties of Thallium include its external appearance, shininess at surface, color, etc. Properties like density, viscosity, melting and boiling point are also covered in this section. At room temperature, this metal is a Silvery White Solid. It starts melting at 303.50 °C. All these Thallium metal properties together define what is Thallium?

Modern Periodic Table

Modern Periodic Table
Group →

Period ↓

1

2

3

4

5

6

7

1

H

2

3

La-Lu
Ac-Lr

4

5

6

7

8

9

10

11

12

13

B

14

C
Si
Ge

15

N
P
As
Sb

16

O
S
Se
Te

17

F
Cl
Br
I
At

18

He
Ne
Ar
Kr
Xe
Rn
Og