Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
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.
It belongs to group 17 of the periodic table having trivial name halogens.
Read key information and facts about element Astatine
|Appearance||unknown, probably metallic|
|Group in Periodic Table||17|
|Group Name||fluorine family|
|Period in Periodic Table||period 6|
|Block in Periodic Table||p -block|
|Electronic Configuration||[Xe] 4f14 5d10 6s2 6p5|
|Electronic Shell Structure (Electrons per shell)||2, 8, 18, 32, 18, 7|
|Melting Point||575 K|
How to Locate Astatine on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. 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.
The element Astatine was discovered by R. Corson,R. MacKenzie and E. Segrè in year 1940 in United States. Astatine was first isolated by in . Astatine derived its name from the Greek astatos, 'unstable'.
Obtained by bombarding bismuth with alpha particles. Later determined to occur naturally in minuscule quantities (<25 grams in earth's crust).
Astatine Presence: Abundance in Nature and Around Us
The table below shows the abundance of Astatine in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
|ppb by weight (1ppb =10^-7 %)||ppb by atoms (1ppb =10^-7 %)|
|Abundance in Universe||-||-|
|Abundance in Sun||-||-|
|Abundance in Meteorites||-||-|
|Abundance in Earth's Crust||-||-|
|Abundance in Oceans||-||-|
|Abundance in Humans||-||-|
Crystal Structure of Astatine
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 three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges 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.
|Space Group Name||-|
|Oxidation States||Space Group Number||-|
|Crystal Structure||Face Centered Cubic|
Astatine Atomic and Orbital Properties
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.
|Number of Electrons (with no charge)||85|
|Number of Protons||85|
|Number of Neutrons||125|
|Shell structure (Electrons per energy level)||2, 8, 18, 32, 18, 7|
|Electron Configuration||[Xe] 4f14 5d10 6s2 6p5|
|Valence Electrons||6s2 6p5|
|Main Oxidation States||-1, 1|
|Oxidation States||-1, 1, 3, 5, 7|
|Atomic Term Symbol (Quantum Numbers)||2P3/2|
Bohr Atomic Model of Astatine - Electrons per energy level
Ground State Electronic Configuration of Astatine - neutral Astatine atom
Abbreviated electronic configuration of Astatine
The ground state abbreviated 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 6s2 6p5, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Astatine
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
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
Atomic Structure of Astatine
Astatine atomic radius is 127 pm, while it's covalent radius is - .
|Atomic Radius Calculated|
127 pm (1.27 Å)
|Atomic Radius Empirical|
- (0 Å)
|Van der Waals Radius||202 pm|
|Neutron Cross Section||-|
|Neutron Mass Absorption||-|
Atomic Spectrum of Astatine
Astatine Chemical Properties: Astatine Ionization Energies and electron affinity
The electron affinity of Astatine is 270.1 kJ/mol.
Ionization Energy of Astatine
Refer to table below for Ionization energies of Astatine
|Ionization energy number||Enthalpy - kJ/mol|
Astatine Physical Properties
Refer to below table for Astatine Physical Properties
Hardness of Astatine - Tests to Measure of Hardness of Element
Astatine Electrical Properties
Astatine is Conductor of electricity. Refer to table below for the Electrical properties ofAstatine
Astatine Heat and Conduction Properties
|Thermal Conductivity||2 W/(m K)|
Astatine Magnetic Properties
|Mass Magnetic Susceptibility||-|
|Molar Magnetic Susceptibility||-|
|Volume Magnetic Susceptibility||-|
Optical Properties of Astatine
Acoustic Properties of Astatine
|Speed of Sound||-|
Astatine Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Astatine
|Melting Point||575 K (301.85°C, 575.33 °F)|
|Boiling Point||- (-273.15°C, -459.66999999999996 °F)|
Enthalpies of Astatine
|Heat of Fusion||6 kJ/mol|
|Heat of Vaporization||40 kJ/mol|
|Heat of Combustion||-|
Astatine Isotopes - Nuclear Properties of Astatine
Astatine has 31 isotopes, with between 193 and 223 nucleons. Astatine has 0 stable naturally occuring isotopes.
Isotopes of Astatine - Naturally occurring stable Isotopes: -.
|Isotope||Z||N||Isotope Mass||% Abundance||T half||Decay Mode|