Element 90 of Periodic table is
Thorium with atomic number 90,
atomic weight 232.0381.
Thorium, symbol Th, has a
Face Centered Cubic structure and Silver color.
Thorium is a actinide element.
Know everything about Thorium Facts, Physical Properties, Chemical
Properties, Electronic configuration, Atomic and Crystal Structure.
Thorium is a chemical element with symbol Th and atomic number 90. A radioactive actinide metal, thorium is one of only two significantly radioactive elements that still occur naturally in large quantities as a primordial element (the other being uranium). It was discovered in 1828 by the Norwegian Reverend and amateur mineralogist Morten Thrane Esmark and identified by the Swedish chemist Jöns Jakob Berzelius, who named it after Thor, the Norse god of thunder.
Read key information and facts about element Thorium
Explore our interactive periodic table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of
The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and
ends at bottom right (atomic number 118). Therefore you can directly look for atomic number
90 to find Thorium on periodic table.
Another way to read periodic table and locate an element is by using group number (column)
and period number (row). To locate Thorium on periodic
table look for cross section of group N/A and period
7 in the modern periodic table.
Interactive Periodic Table to Understand
and Learn Cool Trends
The element Thorium was discovered by Jöns Jakob Berzelius in year
1829 in Sweden
derived its name from Thor, the Scandinavian god of thunder
The table below shows the abundance of Thorium in Universe, Sun, Meteorites,
Earth's Crust, Oceans and Human Body.
The solid state structure of Thorium is Face Centered Cubic.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in
dimensional space to form the structure.
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell
Lattice Constants (a, b and c)
and the angles between them Lattice Angles (alpha, beta and gamma).
The positions of the atoms inside the unit cell are described by the set of atomic positions (
xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible
symmetric arrangements of particles in three-dimensional space are described by the 230 space groups
(219 distinct types, or 230 if chiral copies are considered distinct.
Thorium atoms have 90 electrons and
the electronic shell structure is [2, 8, 18, 32, 18, 10, 2] with Atomic Term Symbol (Quantum Numbers) 3F2.
Shell Structure of Thorium - Electrons per energy
The ground state electronic configuration of Neutral Thorium atom is
[Rn] 6d2 7s2.
The portion of Thorium configuration that is equivalent to the noble gas of
the preceding period, is abbreviated as [Rn]. For atoms with many electrons, this
notation can become lengthy and so an abbreviated notation is used.This is important as it is
the Valence electrons 6d2 7s2, electrons in
the outermost shell that determine the chemical properties of the element.
Complete ground state electronic configuration for the Thorium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 6d2 7s2
Thorium atomic radius is 180 pm, while it's covalent radius is N/A.
The electron affinity of Thorium is N/A
Refer to table below for Ionization energies of Thorium
Refer to below table for Thorium Physical Properties
Thorium is Conductor of electricity. Refer to
below for the Electrical properties of Thorium
Refer to table below for Thermal properties of Thorium
Isotopes of rhodium. Naturally occurring Thorium has
1 stable isotope -
List of unique identifiers to search the element in various chemical registry databases