Origin / Meaning of the name Thorium
Thorium was named after Thor, the Norse God of War.

Periodic Table Group and Classification of the of the Thorium Element
Elements can be classified based on their physical states (States of Matter) e.g. gas, solid or liquid. This element is a solid. Thorium is classified as an element in the Actinide series as one of the "Rare Earth Elements" which can located in Group 3 elements of the Periodic Table and in the 6th and 7th periods. The Rare Earth Elements are of the Lanthanide and Actinide series. Most of the elements in the Actinide series are synthetic or man-made. Nearly 75% of all the elements in the Periodic Table are classified as metals which are detailed in the List of Metals.

Facts about the Discovery and History of the Thorium Element
Thorium was discovered by Jons Jacob Berzelius  in Sweden in 1828.

History of the Periodic Table
Check out the brief History of the Periodic Table which details dates and the names of famous scientists and chemists who contributed to the development of the Periodic Table.

Occurrence of the Thorium Element
Monazite is the primary source of thorium

Abundances of the element in different environments
% in Universe 4×10^-8%
% in Sun 3×10^-8%
% in Meteorites 3.9×10^-6%
% in Earth's Crust 0.0006%
% in Oceans 4×10-12%
% in Humans None

Associated Uses of Thorium
Nuclear fuel
Uranium and thorium has been used to date hominid fossils.

The Properties of the Thorium Element
Name of Element : Thorium
Symbol of Element : Th
Atomic Number of Thorium : 90
Atomic Mass: 232.0381 amu
Melting Point: 1750.0 °C - 2023.15 °K
Boiling Point: 4790.0 °C - 5063.15 °K
Number of Protons/Electrons in Thorium : 90
Number of Neutrons in Thorium : 142
Crystal Structure: Cubic
Density @ 293 K: 11.72 g/cm3
Color of Thorium : silvery

Thorium as on the Periodic Table
Check out Thorium on the Periodic Table which arranges each chemical element according to its atomic number, as based on the Periodic Law, so that chemical elements with similar properties are in the same column. Our Periodic Table is simple to use - just click on the symbol for Thorium as on the Periodic Table for additional information and for an instant comparison of the Atomic Weight, Melting Point, Boiling Point and Mass - G/cc with any other element. An invaluable source of facts and information as a Chemistry reference guide.

What is Thorium - IUPAC and the Modern Standardised Periodic Table
The Standardised Periodic Table in use today was agreed by the International Union of Pure Applied Chemistry, IUPAC, in 1985 and now recognises more periods and elements than Dimitri  Mendeleev knew in his day in his day but still all fitting into his concept of  the "Periodic Table" in which Thorium is just one element that can be found.

Learn about what is Thorium with these fast facts...
These articles contain facts and information relating to Thorium and each of the other elements including the Periodic Symbol,  group, classification, properties and atomic number which is often referred to as the Periodic Table Number. Test your knowledge of chemistry and the Periodic Table by completing the Element Symbols and Atomic Numbers on our Blank Periodic Table. Chemistry students will also find a helpful section on Chemical Formulas.