Astaat
85
At
Groep
17
Periode
6
Blok
p
Protonen
Elektronen
Neutronen
85
85
125
Algemene Eigenschappen
Atoomnummer
85
Atomair gewicht
[210]
Massa Getal
210
Categorie
Halogenen
Kleur
Zilver
Radioactief
Ja
From the Greek astatos meaning unstable
Kristalstructuur
n.v.t.
Historie
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.
Eletronen per schil
2, 8, 18, 32, 18, 7
Electronconfiguratie
[Xe] 4f14 5d10 6s2 6p5
Astatine is preferentially concentrated in the thyroid gland
Fysieke Eigenschappen
Fase
Vast
Dichtheid
7 g/cm3
Smeltpunt
575,15 K | 302 °C | 575,6 °F
Kookpunt
610,15 K | 337 °C | 638,6 °F
Fusiewarmte
6 kJ/mol
Verdampingswarmte
40 kJ/mol
Specifieke Warmtecapaciteit
-
Overvloedig aanwezig in de aardkorst
n.v.t.
Overvloedig aanwezig in het universum
n.v.t.
Verdiensten voor afbeeldingen: pauli.uni-muenster.de
Emilio Segrè, one of the discoverer of the element
CAS-nummer
7440-68-8
PubChem CID nummer
n.v.t.
Atoomeigenschappen
Atoomstraal
-
Covalentiestraal
150 pm
Electronegativiteit
2,2 (Pauling schaal)
Ionisatiepotentiaal
9,3 eV
Atoomvolume
30 cm3/mol
Thermische geleiding
0,017 W/cm·K
Oxidatietoestanden
-1, 1, 3, 5, 7
Toepassingen
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
Isotopen
Stabiele isotopen
-Instabiele isotopen
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