Astatine (At) – Periodic Table [Element Information & More]

Astatine element (At) is in group 17 and period 6 of a periodic table. Astatine is in the p-block and it is classified as a halogen group element on the periodic table.

There is a lot more information related to astatine which is mentioned in the Information Table given below.

So let’s dive right into it!

Table of contents

• Astatine element (Information Table)
• Astatine element in Periodic table
• Facts about Astatine
• Properties of Astatine
• Uses of Astatine

Astatine Element (Information Table)

The important data related to astatine element is given in the table below.

Appearance of astatine	Dark gray (predicted)
Atomic number of astatine	85
Symbol of astatine	At
Atomic mass of astatine (most stable isotope)	210 u
Protons, Neutrons & Electrons in astatine	Protons: 85, Neutrons: 125, Electrons: 85
State of astatine (at STP)	Solid
Group number of astatine in periodic table	17
Period number of astatine in periodic table	6
Block of astatine in periodic table	p-block
Category of astatine	Halogen
Bohr model or Electrons per shell or Electrons arrangement in astatine	2, 8, 18, 32, 18, 7
Electron configuration of astatine	[Xe] 4f14 5d10 6s2 6p5
Orbital diagram of astatine
Valence electrons in astatine	7
Electronegativity of astatine (on pauling scale)	2.2
Atomic radius of astatine (van der Waals radius)	202 picometers
Density of astatine	no data
1st ionization energy of astatine	9.5 eV
Main isotope of astatine	210At and 211At
Crystal structure of astatine	Face Centered Cubic (FCC)
Discovery of astatine	By Emilio Segre, Dale Corson, Kenneth Ross Mackenzie (in 1940)

Also see: Interactive Periodic Table (It has rotating bohr models as well as many other details of all the 118 elements in a single periodic table).

Astatine element in Periodic table

The Astatine element (At) has the atomic number 85 and is located in group 17 and period 6. Astatine is a nonmetal and it is classified as a halogen element.

Click on above elements in the periodic table to see their information.

Facts about astatine

Here are a few interesting facts about the astatine element.

1. Emilio Segre, Dale Corson and Kenneth Ross Mackenzie discovered astatine in the year 1940.
2. Astatine was given its name from the Greek word “astatos”, which means unstable.
3. The quantity of astatine is very less in the earth’s crust.
4. There are around 32 isotopes of astatine and all these isotopes are radioactive in nature.
5. ²¹⁰At is the longest lived isotope of astatine and it has a half life of only 8.3 hours.

Properties of astatine

Here is a list of some physical properties and chemical properties of astatine.

Physical properties of astatine

• Astatine is solid at standard temperature and pressure.
• It has been predicted that astatine has a dark gray appearance.
• The stable isotope of astatine has a predicted atomic mass of 210 amu.

Chemical properties of astatine

• Astatine is a highly radioactive element.
• Astatine reacts with metals to form salts, which is similar to the properties of halogens.
• Astatine is the least reactive halogen and it also has some metallic properties.
• Astatine reacts with water to form hydroastatic acid.
• Astatine forms hydrogen astatide when it reacts with hydrogen gas.

Uses of astatine

Here are some uses of the astatine element.

• Astatine is very reactive and it has a short half-life. So it does not have many applications. It is generally used for research work.
• ²¹¹At is the isotope of astatine which can be used to treat cancer.

External resources:

1. Astatine – Element information, properties and uses | Periodic Table. (n.d.). Astatine – Element Information, Properties and Uses | Periodic Table. https://www.rsc.org/periodic-table/element/85/astatine
2. Astatine – Wikipedia. (2015, February 24). Astatine – Wikipedia. https://en.wikipedia.org/wiki/Astatine
3. P. (n.d.). Astatine | At (Element) – PubChem. Astatine | at (Element) – PubChem. https://pubchem.ncbi.nlm.nih.gov/element/Astatine
4. It’s Elemental – The Element Astatine. (n.d.). It’s Elemental – the Element Astatine. https://education.jlab.org/itselemental/ele085.html
5. Astatine (At) | AMERICAN ELEMENTS ® (n.d.). American Elements: The Materials Science Company. https://www.americanelements.com/at.html
6. CORSON, D. R., MACKENZIE, K. R., & SEGRÈ, E. (1947, January). Astatine : The Element of Atomic Number 85. Nature, 159(4027), 24–24. https://doi.org/10.1038/159024b0
7. James A. M. & Lord M. P. (1992). Macmillan’s chemical and physical data. Macmillan.
8. Bedford, et al. (1996, April 1). Recommended values of temperature on the International Temperature Scale of 1990 for a selected set of secondary reference points. Metrologia, 33(2), 133–154. https://doi.org/10.1088/0026-1394/33/2/3
9. Allred, A. (1961, June). Electronegativity values from thermochemical data. Journal of Inorganic and Nuclear Chemistry, 17(3–4), 215–221. https://doi.org/10.1016/0022-1902(61)80142-5
10. Periodic Table of Elements: Los Alamos National Laboratory. (n.d.). Periodic Table of Elements: Los Alamos National Laboratory. https://periodic.lanl.gov/85.shtml
11. Atomic Data for Astatine (At). (n.d.). Atomic Data for Astatine (At). https://physics.nist.gov/PhysRefData/Handbook/Tables/astatinetable1.htm
12. Astatine | At | ChemSpider. (n.d.). Astatine | at | ChemSpider. http://www.chemspider.com/Chemical-Structure.4573995.html?rid=b6e70b4c-6eec-4cf0-bb9a-c7ef63a6bf39&page_num=0
13. Possolo, et al. (2018, January 4). Interpreting and propagating the uncertainty of the standard atomic weights (IUPAC Technical Report). Pure and Applied Chemistry, 90(2), 395–424. https://doi.org/10.1515/pac-2016-0402
14. Emsley, J. (2011). Nature’s Building Blocks: An A-Z Guide to the Elements. United Kingdom: OUP Oxford.
15. Haynes, W. M. (Ed.). (2014, June 4). CRC Handbook of Chemistry and Physics. https://doi.org/10.1201/b17118
16. Electronic structure of the elements. (2000, March). The European Physical Journal C, 15(1–4), 78–79. https://doi.org/10.1007/bf02683401