Astat

85
At
Grupp
17
Period
6
Block
p
Protoner
Electrons
Neutroner
85
85
125
Generella Egenskaper
Atomnummer
85
Atommassa
[210]
Mass Number
210
Kategori
Halogener
Färg
Silver
Radioaktiv
Ja
From the Greek astatos meaning unstable
Kristallstruktur
n/a
Historia
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.
Elektroner per skal
2, 8, 18, 32, 18, 7
Elektronkonfiguration
[Xe] 4f14 5d10 6s2 6p5
At
Astatine is preferentially concentrated in the thyroid gland
Fysikaliska Egenskaper
Aggregationstillstånd
Fast
Densitet
7 g/cm3
Smältpunkt
575,15 K | 302 °C | 575,6 °F
Kokpunkt
610,15 K | 337 °C | 638,6 °F
Smältvärme
6 kJ/mol
Ångbildningsvärme
40 kJ/mol
Specifik värmekapacitet
-
Abundance in Earth's crust
n/a
Abundance in Universe
n/a
Emilio
Bildkrediter: pauli.uni-muenster.de
Emilio Segrè, one of the discoverer of the element
CAS Number
7440-68-8
PubChem CID Number
n/a
Atomära Egenskaper
Atomradie
-
Kovalent radie
150 pm
Elektronegativitet
2,2 (Paulingskalan)
Jonisationspotential
9,3 eV
Molvolym
30 cm3/mol
Värmeledningsförmåga
0,017 W/cm·K
Oxidationstillstånd
-1, 1, 3, 5, 7
Applications
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.
Astatine is highly radioactive
Isotoper
Stabila isotoper
-
Instabila isotoper
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