Astatine including Technical Data, Safety Data and its High Purity properties, research, applications and other useful facts are discussed below. Scientific facts such as the atomic structure,ionization energy, abundance on Earth, conductivity and thermal properties are included. 

Astatine is a Block P, Group 17, Period 6 element. The number of electrons in each of Astatine‘s shells is 2, 8, 18, 32, 18, 7 and its electronic configuration is [Xe] 4f145d10 6s2 6p5. In its elemental form Astatine‘s CAS number is 7440-68-8. The Astatine atom has a radius of 145.pm and it‘s Van der Waals radius is 200.pm. Astatine is highly radioactive. The amount of naturally occurring astatine in the world is about 25g. 

Astatine is the rarest naturally occurring non-transuranic element. Astatine was discovered by Emilio Gino Segrè, Dale R. Corson and K. R. MacKenzie  in 1940. 

Astatine Abundance. The following table shows the abundance of Astatine and each of its naturally occurring isotopes on Earth along with the atomic mass for each isotope. Isotope Atomic Mass % Abundance on Earth At-210 209.987131 - Astatine Safety Data. The safety data for Astatine metal, nanoparticles and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the left margin. Asatinecompounds have no biological role.  Ionization Energy. The ionization energy for Astatine (the least required energy to release a single electron from the atom in it‘s ground state in the gas phase) is stated in the following table: 1st Ionization Energy - kJ mol-1 2nd Ionization Energy - kJ mol-1 3rd Ionization Energy - kJ mol-1 Conductivity. As to Astatine‘s electrical and thermal conductivity, the electrical conductivity measured in terms of electrical resistivity @ 20 ?C is 16.9 ?Ocm and its electronegativities (or its ability to draw electrons relative to other elements) is 2.1. The thermal conductivity of Astatine is 50.6 W m-1 K-1.  Thermal Properties of Astatine. The melting point and boiling point for Astatine are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization. Heat of Fusion 23.81 kJ mol-1 Heat of Vaporization 585.22 kJ mol-1 Heat of Atomization 678 kJ mol-1

Formula	Atomic Number	Molecular Weight	Electronegativity (Pauling)	Density	Melting Point	Boiling Point	Vanderwaals radius	Ionic radius	Energy of first ionization
At	17	(210) g.mol -1	2.2	-?g·cm?3	302? °C	337? °C	.200 nm	- pm	- kJ.mol-1