Astat

85
At
Skupina
17
Perioda
6
Blok
p
Protons
Electrons
Neutrons
85
85
125
General Properties
Vrstno število
85
Atomska teža
[210]
Mass Number
210
Kategorija
Halogeni
Barva
Silver
Radioactive
Da
From the Greek astatos meaning unstable
Kristalna struktura
n/a
Zgodovina
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.
Electrons per shell
2, 8, 18, 32, 18, 7
Razporeditev elektronov
[Xe] 4f14 5d10 6s2 6p5
At
Astatine is preferentially concentrated in the thyroid gland
Physical Properties
Faza snovi
Trdnina
Gostota
7 g/cm3
Tališče
575,15 K | 302 °C | 575,6 °F
Vrelišče
610,15 K | 337 °C | 638,6 °F
Talilna toplota
6 kJ/mol
Izparilna toplota
40 kJ/mol
Toplotna kapaciteta
-
Abundance in Earth's crust
n/a
Abundance in Universe
n/a
Emilio
Zasluge za slike: pauli.uni-muenster.de
Emilio Segrè, one of the discoverer of the element
CAS Number
7440-68-8
PubChem CID Number
n/a
Atomic Properties
Atomski polmer
-
Kovalentni polmer
150 pm
Elektronegativnost
2,2 (Paulingova lestvica)
Ionization Potential
9,3 eV
Atomic Volume
30 cm3/mol
Toplotna prevodnost
0,017 W/cm·K
Oksidacijska stanja
-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
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