Astat
85
At
Gruppe
17
Periode
6
Blokk
p
Protons
Electrons
Neutrons
85
85
125
Generelle eigenskapar
Atomnummer
85
Atommasse
[210]
Mass Number
210
Kategori
Halogen
Farge
Silver
Radioactive
Ja
From the Greek astatos meaning unstable
Krystallstruktur
n/a
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.
Elektron per energinivå
2, 8, 18, 32, 18, 7
Elektronkonfigurasjon
[Xe] 4f14 5d10 6s2 6p5
Astatine is preferentially concentrated in the thyroid gland
Fysiske eigenskapar
Tilstandsform
Fast stoff
Tettleik
7 g/cm3
Smeltepunkt
575,15 K | 302 °C | 575,6 °F
Kokepunkt
610,15 K | 337 °C | 638,6 °F
Smeltevarme
6 kJ/mol
Fordampingsvarme
40 kJ/mol
Spesifikk varmekapasitet
-
Abundance in Earth's crust
n/a
Abundance in Universe
n/a
CAS Number
7440-68-8
PubChem CID Number
n/a
Atom eigenskapar
Atomradius
-
Kovalent radius
150 pm
Elektronegativitet
2,2 (Paulings skala)
Ioniseringspotensial
9,3 eV
Molart volum
30 cm3/mol
Termisk konduktivitet
0,017 W/cm·K
Oksidasjonstrinn
-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.
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
Isotopes
Stable Isotopes
-Unstable Isotopes
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