At - Astatine
Astatine 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. You can also download Printable Periodic Table of Elements Flashcards for Astatine in a PDF format.
Astatine Facts
Read key information and facts about element Astatine
Name | Astatine |
Atomic Number | 85 |
Atomic Symbol | At |
Atomic Weight | 210 |
Phase | Solid |
Color | Silver |
Appearance | unknown, probably metallic |
Classification | Halogens |
Natural Occurance | From decay |
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 |
Boiling Point | - |
CAS Number | CAS7440-68-8 |
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.
Astatine History
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'.
Discovered By | R. Corson,R. MacKenzie and E. Segrè |
Discovery Date | 1940 in United States |
First Isolation | |
Isolated by |
Obtained by bombarding bismuth with alpha particles. Later determined to occur naturally in minuscule quantities (<25 grams in earth's crust).
Astatine Uses
Astatine is used as a radioactive tracer and in cancer treatment.
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)
a | b | c |
---|---|---|
and the angles between them Lattice Angles (alpha, beta and gamma).
alpha | beta | 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 | - |
Space Group Number | - |
Crystal Structure | Face Centered Cubic |
Number of atoms per unit cell | 4 |
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
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.
Atomic Number | 85 |
Number of Electrons (with no charge) | 85 |
Number of Protons | 85 |
Mass Number | 210 |
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 |
Valence (Valency) | 7 |
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
n | s | p | d | f |
---|
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.
As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
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 | - |
Atomic Volume | - |
Covalent Radius | - |
Van der Waals Radius | 202 pm |
Neutron Cross Section | - |
Neutron Mass Absorption | - |
Spectral Lines of Astatine - Atomic Spectrum of Astatine
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules.
Spectral lines are the result of interaction between a quantum system and a single photon. A spectral line may be observed either as an emission line or an absorption line.
Spectral lines are highly atom-specific, and can be used to identify the chemical composition of any medium. Several elements, including helium, thallium, and caesium, were discovered by spectroscopic means. They are widely used to determine the physical conditions of stars and other celestial bodies that cannot be analyzed by other means.
Emission spectrum of Astatine
Emission spectrum of Astatine is not available
Absorption spectrum of Astatine
Absorption spectrum of Astatine is not available
Astatine Chemical Properties: Astatine Ionization Energies and electron affinity
The electron affinity of Astatine is 270.1 kJ/mol.
Valence | 7 |
Electronegativity | 2.2 |
ElectronAffinity | 270.1 kJ/mol |
Ionization Energy of Astatine
Ionization energy is the amount of energy required to remove an electron from an atom or molecule.in chemistry, this energy is expresed in kilocalories per mole (kcal/mol) or kilojoules per mole (kJ/mol).
Refer to table below for Ionization energies of Astatine
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1st | 899.003 |
Astatine Physical Properties
Refer to below table for Astatine Physical Properties
Density | - |
Molar Volume | - |
Elastic Properties
Young Modulus | - |
Shear Modulus | - |
Bulk Modulus | - |
Poisson Ratio | - |
Hardness of Astatine - Tests to Measure of Hardness of Element
Mohs Hardness | - |
Vickers Hardness | - |
Brinell Hardness | - |
Astatine Electrical Properties
Electrical resistivity measures element's electrical resistance or how strongly it resists electric current.The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). While Electrical conductivity is the reciprocal of electrical resistivity. It represents a element's ability to conduct electric current. The SI unit of electrical conductivity is siemens per metre (S/m).
Astatine is a -. Refer to table below for the Electrical properties of Astatine
Electrical conductors | - |
Electrical Conductivity | - |
Resistivity | - |
Superconducting Point | - |
Astatine Heat and Conduction Properties
Thermal Conductivity | 2 W/(m K) |
Thermal Expansion | - |
Astatine Magnetic Properties
Magnetic Type | - |
Curie Point | - |
Mass Magnetic Susceptibility | - |
Molar Magnetic Susceptibility | - |
Volume Magnetic Susceptibility | - |
Optical Properties of Astatine
Refractive Index | - |
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, 575.330 °F) |
Boiling Point | - |
Critical Temperature | - |
Superconducting Point | - |
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 |
---|---|---|---|---|---|---|
193At | 85 | 108 | 193 | Synthetic | ||
194At | 85 | 109 | 194 | Synthetic | ||
195At | 85 | 110 | 195 | Synthetic | ||
196At | 85 | 111 | 196 | Synthetic | ||
197At | 85 | 112 | 197 | Synthetic | ||
198At | 85 | 113 | 198 | Synthetic | ||
199At | 85 | 114 | 199 | Synthetic | ||
200At | 85 | 115 | 200 | Synthetic | ||
201At | 85 | 116 | 201 | Synthetic | ||
202At | 85 | 117 | 202 | Synthetic | ||
203At | 85 | 118 | 203 | Synthetic | ||
204At | 85 | 119 | 204 | Synthetic | ||
205At | 85 | 120 | 205 | Synthetic | ||
206At | 85 | 121 | 206 | Synthetic | ||
207At | 85 | 122 | 207 | Synthetic | ||
208At | 85 | 123 | 208 | Synthetic | ||
209At | 85 | 124 | 209 | Synthetic | ||
210At | 85 | 125 | 210 | Synthetic | 8.06 h | BetaPlusDecay |
211At | 85 | 126 | 211 | Synthetic | ||
212At | 85 | 127 | 212 | Synthetic | ||
213At | 85 | 128 | 213 | Synthetic | ||
214At | 85 | 129 | 214 | Synthetic | ||
215At | 85 | 130 | 215 | Synthetic | ||
216At | 85 | 131 | 216 | Synthetic | ||
217At | 85 | 132 | 217 | Synthetic | ||
218At | 85 | 133 | 218 | Synthetic | ||
219At | 85 | 134 | 219 | Synthetic | ||
220At | 85 | 135 | 220 | Synthetic | ||
221At | 85 | 136 | 221 | Synthetic | ||
222At | 85 | 137 | 222 | Synthetic | ||
223At | 85 | 138 | 223 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
The United States Department of Transportation (DOT) identifies hazard class of all dangerous elements/goods/commodities either by its class (or division) number or name. The DOT has divided these materials into nine different categories, known as Hazard Classes.
NFPA 704 is a Standard System for the Identification of the Hazards of Materials for Emergency Response. NFPA is a standard maintained by the US based National Fire Protection Association.
The health (blue), flammability (red), and reactivity (yellow) rating all use a numbering scale ranging from 0 to 4. A value of zero means that the element poses no hazard; a rating of four indicates extreme danger.
NFPA Fire Rating | N/A | N/A |
NFPA Health Rating | N/A | N/A |
NFPA Reactivity Rating | N/A | N/A |
NFPA Hazards | N/A |
Autoignition Point | - |
Flashpoint | - |
Database Search
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS7440-68-8 |
RTECS Number | - |
CID Number | - |
Gmelin Number | - |
NSC Number | - |
Compare Astatine with other elements
Compare Astatine with Group 17, Period 6 and Halogens elements of the periodic table.
Compare Astatine with all Group 17 elements
Compare Astatine with all Period 6 elements
Compare Astatine with all Halogens elements
Frequently Asked Questions (FAQ)
Find the answers to the most frequently asked questions about Astatine