Elements
90

Th

Thorium

Pronounced

THOR-i-em

Thorium (Th) is a silvery-white colored radioactive metal that has the atomic number 90 in the periodic table. It is an Actinoid Metal with the symbol Th.

Thorium is named after the norse god of thunder, Thor. Thorium was first thought to have been discovered in 1815 by Jöns Jakob Berzelius however in 1824 it was proven to be Yttrium. It was not until 1828 when Berzelius was analysing a Norwegian mineral that he discovered the unknown element Thorium. As a liquid Thorium has a wider temperature range between its boiling and melting points than any other element. It is about as abundant as lead in the earth’s crust but does not exist in its natural state. It is been used since 1885 in the creation of gas mantles and gas lamps and is also used to strengthen wires as an alloy. Thorium is seen as a potential alternative to uranium in nuclear reactors as it is more easily extracted and it is more abundant in the earths crust. It is a solid metal at room temperature and it has a melting point of 1750°c and a boiling point of 4790°c.

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FAQ's

What is the Melting Point for Thorium?

Thorium has a Melting Point of 1750°C, meaning at 1750°C it will turn to a liquid.

What is the Boiling Point for Thorium?

Thorium has a Boiling Point of 4790°C, meaning at 4790°C it will turn to a Gas.

What is the Electronegativity of Thorium?

Thorium's Electronegativty is 1.3. Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.

Discovered by

Jöns Berzelius

Discovery date

1828

What is the Heat of Vaporization of Thorium?

Thorium has a Heat of Vaporization of 514.4 kJ/mol.

Uses

Used in making strong alloys. Also in ultraviolet photoelectric cells. It is a common ingredient in high-quality lenses. Bombarded with neutrons make uranium-233, a nuclear fuel.

Sources

Found in various minerals like monazite and thorite.

90
Protons
90
Electrons
142
Neutrons

Th

Element Symbol
Th
Atomic Weight
232.038
Atomic Number
90
State
Solid
Melting Point
Unknown
1750
°C
Boiling Point
4790
Unknown
°C
Heat of Vaporization
514.4
Unknown
kJ/mol
Crystal Structure
Cubic: Face centered
Thermoconductivity
0.54
Unknown
W/cmK
Shells
2,8,18,32,18,10,2
Group
Actinide
Period
7
Block
F Block
Orbitals
[Rn] 6d2 7s2
Coefficient of Thermal Expansion
11.0 10^-6 K^-1
Covalent Radius
1.65 Å
Density at 293K
11.7 g/cm³
Electrical Conductivity
0.0653 10^6/cm ohm
First Ionization Potential
6.08 V
Second Ionization Potential
11.504 V
Third Ionization Potential
20.003 V
Ionic Radius
1.05 (+4) Å
Oxydation States
4
Lattice Parameter
5.0847 Å
Lattice Parameter 2
--
Lattice Parameter 3
4.887 Å
Orbital configuration
2,8,18,32,18,10,2

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Explore Other Actinides

The actinide series contains 15 metallic elements from number 89 (actinium) to 103 (lawrencium). They are located in group 3 in the periodic table.
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Actinium

89
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Protactinium

91