Astatiniu
85
At
Grupă
17
Perioadă
6
Bloc
p
Protoni
Electroni
Neutroni
85
85
125
Proprietăți Generale
Număr atomic
85
Masă atomică
[210]
Numar de masa
210
Categorie
Halogeni
Culoare
Argint
Radioactive
Da
Din greacă astatos, însemnând instabil
Structură cristalină
n/a
Istoric
In 1869, existence of astatine was first predicted by Russian chemist Dmitri Mendeleev and called the element eka-iodine.
In 1940, Dale R. Corson, Kenneth Ross MacKenzie, and Emilio Segrè isolated the element at the University of California, Berkeley.
Instead of searching for the element in nature, the scientists created it by bombarding bismuth-209 with alpha particles.
In 1940, Dale R. Corson, Kenneth Ross MacKenzie, and Emilio Segrè isolated the element at the University of California, Berkeley.
Instead of searching for the element in nature, the scientists created it by bombarding bismuth-209 with alpha particles.
Electroni pe nivelul de energie
2, 8, 18, 32, 18, 7
Configurație electronică
[Xe] 4f14 5d10 6s2 6p5
Astatine is preferentially concentrated in the thyroid gland
Proprietăți Fizice
Fază
Solid
Densitate
7 g/cm3
Punct de topire
575,15 K | 302 °C | 575,6 °F
Punct de fierbere
610,15 K | 337 °C | 638,6 °F
Energie de fuziune
6 kJ/mol
Energie de evaporare
40 kJ/mol
Căldură specifică
-
Abundența în scoarța Pământului
n/a
Abundența în Univers
n/a
Numarul CAS
7440-68-8
Număr CID PubChem
n/a
Proprietăți Atomice
Rază atomică
-
Rază de covalență
150 pm
Electronegativitate
2,2 (Scara lui Pauling)
Potențial de ionizare
9,3 eV
Volum molar
30 cm3/mol
Conductivitate termică
0,017 W/cm·K
Număr de oxidare
-1, 1, 3, 5, 7
Aplicații
The newly formed astatine-211 is important in nuclear medicine.
Once produced, astatine must be used quickly, as it decays with a half-life of 7.2 hours.
Astatine-211 can be used for targeted alpha particle radiotherapy, since it decays either via emission of an alpha particle.
Once produced, astatine must be used quickly, as it decays with a half-life of 7.2 hours.
Astatine-211 can be used for targeted alpha particle radiotherapy, since it decays either via emission of an alpha particle.
Astatine is highly radioactive
Izotopi
Izotopi stabili
-Izotopi instabili
193At, 194At, 195At, 196At, 197At, 198At, 199At, 200At, 201At, 202At, 203At, 204At, 205At, 206At, 207At, 208At, 209At, 210At, 211At, 212At, 213At, 214At, 215At, 216At, 217At, 218At, 219At, 220At, 221At, 222At, 223At