Element 85 of Periodic table is
Astatine with atomic number 85,
atomic weight 210.
Astatine, symbol At, has a
Face Centered Cubic structure and Silver color.
Astatine is a halogens element.
Trivial name of Astatine is halogens*.
Know everything about Astatine Facts, Physical Properties, Chemical
Properties, Electronic configuration, Atomic and Crystal Structure.
Astatine is a very rare radioactive chemical element with the chemical symbol At and atomic number 85. It occurs on Earth as the decay product of various heavier elements. All its isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours.
Read key information and facts about element Astatine
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
85 to find Astatine 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 Astatine on periodic
table look for cross section of group 17 and period
6 in the modern periodic table.
Interactive Periodic Table to Understand
and Learn Cool Trends
The element Astatine was discovered by Dale R. Corson in year
1940 in United States
derived its name from the Greek astatos, 'unstable'
The table below shows the abundance of Astatine in Universe, Sun, Meteorites,
Earth's Crust, Oceans and Human Body.
The solid state structure of Astatine 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.
Astatine atoms have 85 electrons and
the electronic shell structure is [2, 8, 18, 32, 18, 7] with Atomic Term Symbol (Quantum Numbers) 2P3/2.
Shell Structure of Astatine - Electrons per energy
The ground state electronic configuration of Neutral Astatine atom is
[Xe] 4f14 5d10 6s2 6p5.
The portion of Astatine configuration that is equivalent to the noble gas of
the preceding period, is abbreviated as [Xe]. 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 4f14 5d10 6s2 6p5, electrons in
the outermost shell that determine the chemical properties of the element.
Complete ground state electronic configuration for the Astatine atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p5
Astatine atomic radius is 127 pm, while it's covalent radius is N/A.
The electron affinity of Astatine is 270.1 kJ/mol
Refer to table below for Ionization energies of Astatine
Refer to below table for Astatine Physical Properties
Astatine is N/A of electricity. Refer to
below for the Electrical properties of Astatine
Refer to table below for Thermal properties of Astatine
Isotopes of rhodium. Naturally occurring Astatine has
1 stable isotope -
List of unique identifiers to search the element in various chemical registry databases