Astatine (At) is a chemical element of the periodic table, located in the group 17 and the period 6, and is having the atomic number 85. It is a dark, black, lustrous post transition metal, whose name comes from the Greek word “astatos”, which means unstable. It is highly toxic and is counted as one of the radioactive elements. It is the rarest element on earth and is counted as one of the heaviest elements in the halogen group.
On periodic table
| group | ⇨ | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| period | ⇩ | ||||||||||||||||||
| 1 | 1 H  Hydrogen |
2 He  Helium |
|||||||||||||||||
| 2 | 3 Li  Lithium |
4 Be  Beryllium |
5 B  Boron |
6 C  Carbon |
7 N  Nitrogen |
8 O  Oxygen |
9 F  Fluorine |
10 Ne  Neon |
|||||||||||
| 3 | 11 Na  Sodium |
12 Mg  Magnesium |
13 Al  Aluminium |
14 Si  Silicon |
15 P  Phosphorus |
16 S  Sulfur |
17 Cl  Chlorine |
18 Ar  Argon |
|||||||||||
| 4 | 19 K  Potassium |
20 Ca  Calcium |
21 Sc  Scandium |
22 Ti  Titanium |
23 V  Vanadium |
24 Cr  Chromium |
25 Mn  Manganese |
26 Fe  Iron |
27 Co  Cobalt |
28 Ni  Nickel |
29 Cu  Copper |
30 Zn  Zinc |
31 Ga  Gallium |
32 Ge  Germanium |
33 As  Arsenic |
34 Se  Selenium |
35 Br  Bromine |
36 Kr  Krypton |
|
| 5 | 37 Rb  Rubidium |
38 Sr  Strontium |
39 Y  Yttrium |
40 Zr  Zirconium |
41 Nb  Niobium |
42 Mo  Molybdenum |
43 Tc  Technetium |
44 Ru  Ruthenium |
45 Rh  Rhodium |
46 Pd  Palladium |
47 Ag  Silver |
48 Cd  Cadmium |
49 In  Indium |
50 Sn  Tin |
51 Sb  Antimony |
52 Te  Tellurium |
53 I  Iodine |
54 Xe  Xenon |
|
| 6 | 55 Cs  Caesium |
56 Ba  Barium |
72 Hf  Hafnium |
73 Ta  Tantalum |
74 W  Tungsten |
75 Re  Rhenium |
76 Os  Osmium |
77 Ir  Iridium |
78 Pt  Platinum |
79 Au  Gold |
80 Hg  Mercury |
81 Tl  Thallium |
82 Pb  Lead |
83 Bi  Bismuth |
84 Po  Polonium |
85 At Astatine |
86 Rn  Radon |
||
| 7 | 87 Fr  Francium |
88 Ra  Radium |
104 Rf  Rutherfordium |
105 Db  Dubnium |
106 Sg  Seaborgium |
107 Bh  Bohrium |
108 Hs  Hassium |
109 Mt  Meitnerium |
110 Ds  Darmstadtium |
111 Rg  Roentgenium |
112 Cn  Copernicium |
113 Nh  Nihonium |
114 Fl  Flerovium |
115 Mc  Moscovium |
116 Lv  Livermorium |
117 Ts  Tennessine |
118 Og  Oganesson |
||
| 57 La  Lanthanum |
58 Ce  Cerium |
59 Pr  Praseodymium |
60 Nd  Neodymium |
61 Pm  Promethium |
62 Sm  Samarium |
63 Eu  Europium |
64 Gd  Gadolinium |
65 Tb  Terbium |
66 Dy  Dysprosium |
67 Ho  Holmium |
68 Er  Erbium |
69 Tm  Thulium |
70 Yb  Ytterbium |
71 Lu  Lutetium |
|||||
| 89 Ac  Actinium |
90 Th  Thorium |
91 Pa  Protactinium |
92 U  Uranium |
93 Np  Neptunium |
94 Pu  Plutonium |
95 Am  Americium |
96 Cm  Curium |
97 Bk  Berkelium |
98 Cf  Californium |
99 Es  Einsteinium |
100 Fm  Fermium |
101 Md  Mendelevium |
102 No  Nobelium |
103 Lr  Lawrencium |
|||||
| – p block |
Astatine is a p-block element, found in the seventeenth column (halogen group) of the periodic table, next to polonium (Po), and is denoted by the atomic number 85 and chemical symbol At.
Element information
 |
|
| Origin of name | Greek word “astatos” (which means unstable) |
| Symbol | At |
| Atomic number (Z) | 85 |
| Atomic mass | (210) |
| Block | p-block |
| Group | 17 (halogen) |
| Period | 6 |
| Classification | Post-transition metal |
| Electron configuration | [Xe] 4f14 5d10 6s2 6p5 |
| Electrons per shell | 2, 8, 18, 32, 18, 7 |
| Learn how to draw: Astatine Bohr model | |
| Phase at r.t | Solid (predicted) |
| Density near r.t | 8.91-8.95 g/cm3 (estimated) |
| Natural occurrence | From decay |
| Oxidation state | -1, +1 |
| Protons Neutrons Electrons |
85 125 85 |
| Valence electrons | 7 |
| Learn how to find: Astatine valence electrons | |
| CAS number | 7440-68-8 |
| Discovered by | Dale R. Corson, Kenneth Ross MacKenzie, and Emilio Segrè in 1940 |
History
Astatine is a highly radioactive element that was first discovered in 1940 by Dale Corson, K.R. MacKenzie, and Emilio Segrè at the University of California, Berkeley. Astatine was the last naturally occurring element to be discovered, as it is very rare and occurs only in minute quantities in nature. Its name derives from the Greek word “astatos,” meaning unstable.
Prior to its discovery, astatine was predicted to exist based on the periodic table, which suggested that an element should exist between iodine and xenon. The prediction was made by the chemist Fred Allison in 1931, but it was not until 1940 that the first sample of astatine was produced. The researchers produced astatine by bombarding bismuth with alpha particles in a cyclotron, which caused a nuclear reaction that resulted in the formation of astatine.
Since its discovery, astatine has been produced in very small quantities in laboratories by bombarding heavy elements with energetic particles. Its extreme rarity and radioactivity make it difficult to study, so much of what is known about astatine comes from theoretical predictions based on its position in the periodic table.
Occurrence and production
Astatine is a rare element that occurs naturally in trace amounts in uranium and thorium ores. It is produced artificially by bombarding bismuth-209 with alpha particles. The first synthesis of astatine was in 1940 by Dale R. Corson, Kenneth Ross MacKenzie, and Emilio G. Segrè at the University of California, Berkeley. They produced astatine-211 by bombarding bismuth-209 with alpha particles. Since then, astatine has been produced by several other methods, including bombarding bismuth-209 with heavy ions, such as neon or helium, and by irradiating thorium or uranium with protons or alpha particles. Astatine is extremely rare, with only a few milligrams thought to exist on Earth at any given time. As a result of its rarity, astatine is primarily used for research purposes in the field of nuclear medicine.
Properties
Astatine is a highly radioactive element and the heaviest halogen.
It exists in several isotopes, but the most stable one has a half-life of only 8.1 hours.
Astatine is a rare element and is one of the least abundant elements on Earth.
It is solid at room temperature and appears to be black or dark gray in color.
Astatine is highly reactive and can form compounds with hydrogen, oxygen, and other elements.
It is a strong oxidizing agent and can react with metals, nonmetals, and metalloids.
Astatine has a high electron affinity and electronegativity, making it a good halogen and a potential candidate for certain medical applications.
Applications
Due to its radioactivity and short half-life, astatine has no practical applications outside of scientific research.
It has been used in studies related to cancer treatment and diagnosis, particularly in the development of targeted alpha particle therapy, which uses alpha particles emitted by radioactive isotopes to specifically target cancer cells.
Astatine has also been used in studies related to the synthesis of heavy elements and the prediction of their properties, as well as in studies of chemical bonding and the structure of molecules.
Astatine’s scarcity and high cost make it difficult to obtain and work with, limiting its potential applications.
Interesting facts
Astatine is one of the rarest naturally occurring elements, with less than one gram of it estimated to exist at any given time on Earth.
Due to its rarity, there are no known commercial applications for astatine.
Astatine is the heaviest of the halogen group of elements, which includes fluorine, chlorine, bromine, and iodine.
Astatine has a very short half-life, with its isotopes decaying quickly into other elements through alpha or beta decay.
Astatine has been used in small amounts in scientific research to study its behavior and properties, as well as in medical applications such as targeted radiation therapy for cancer treatment.
Related
More elements
External links
- https://www.rsc.org/periodic-table/element/85/astatine
- https://en.wikipedia.org/wiki/Astatine
- https://www.britannica.com/science/astatine
- https://cen.acs.org/physical-chemistry/Astatine-chemistry-puzzle-shows-anticancer/98/i31
- https://www.livescience.com/39514-facts-about-astatine.html
- https://pubchem.ncbi.nlm.nih.gov/element/Astatine
- https://www.chemicool.com/elements/astatine.html
- https://education.jlab.org/itselemental/ele085.html
Deep
Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.
