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.
| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| – p block |
Astatine Element Information
 |
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| 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 |
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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
