Element 89 of Periodic table is
Actinium with atomic number 89,
atomic weight 227.
Actinium, symbol Ac, has a
Face Centered Cubic structure and Silver color.
Actinium is a actinide element.
Know everything about Actinium Facts, Physical Properties, Chemical
Properties, Electronic configuration, Atomic and Crystal Structure.
Actinium is a radioactive chemical element with symbol Ac (not to be confused with the abbreviation for an acetyl group) and atomic number 89, which was discovered in 1899. It was the first non-primordial radioactive element to be isolated. Polonium, radium and radon were observed before actinium, but they were not isolated until 1902.
Read key information and facts about element Actinium
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
89 to find Actinium 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 Actinium 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 Actinium was discovered by Friedrich Oskar Giesel in year
1899 in France
derived its name from the Greek aktis, 'ray'
The table below shows the abundance of Actinium in Universe, Sun, Meteorites,
Earth's Crust, Oceans and Human Body.
The solid state structure of Actinium 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.
Actinium atoms have 89 electrons and
the electronic shell structure is [2, 8, 18, 32, 18, 9, 2] with Atomic Term Symbol (Quantum Numbers) 2D3/2.
Shell Structure of Actinium - Electrons per energy
The ground state electronic configuration of Neutral Actinium atom is
[Rn] 6d1 7s2.
The portion of Actinium 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 6d1 7s2, electrons in
the outermost shell that determine the chemical properties of the element.
Complete ground state electronic configuration for the Actinium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 6d1 7s2
Actinium atomic radius is 195 pm, while it's covalent radius is N/A.
The electron affinity of Actinium is N/A
Refer to table below for Ionization energies of Actinium
Refer to below table for Actinium Physical Properties
Actinium is N/A of electricity. Refer to
below for the Electrical properties of Actinium
Refer to table below for Thermal properties of Actinium
Isotopes of rhodium. Naturally occurring Actinium has
1 stable isotope -
List of unique identifiers to search the element in various chemical registry databases