Astatin

85
At
Golongan
17
Periode
6
Blok
p
Proton
Elektron
Neutron
85
85
125
Sifat Umum
Nomor atom
85
Massa atom
[210]
Nomor massa
210
Kategori
Halogen
Warna
Perak
Radioaktif
Ya
From the Greek astatos meaning unstable
Struktur kristal
n/a
Sejarah
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.
Elektron per kulit
2, 8, 18, 32, 18, 7
Konfigurasi elektron
[Xe] 4f14 5d10 6s2 6p5
At
Astatine is preferentially concentrated in the thyroid gland
Sifat Fisika
Fase
Solid
Kepadatan
7 g/cm3
Titik lebur
575,15 K | 302 °C | 575,6 °F
Titik didih
610,15 K | 337 °C | 638,6 °F
Kalor peleburan
6 kJ/mol
Kalor penguapan
40 kJ/mol
Kapasitas kalor molar
-
Kelimpahan di kerak bumi
n/a
Kelimpahan di alam semesta
n/a
Emilio
Kredit Gambar: pauli.uni-muenster.de
Emilio Segrè, one of the discoverer of the element
Nomor CAS
7440-68-8
PubChem CID Number
n/a
Sifat Atom
Jari-jari atom
-
Jari-jari kovalen
150 pm
Elektronegativitas
2,2 (Skala Pauling)
Potensi Ionisasi
9,3 eV
Volume atom
30 cm3/mol
Kondusivitas termal
0,017 W/cm·K
Bilangan oksidasi
-1, 1, 3, 5, 7
Aplikasi
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
Isotop
Isotop stabil
-
Isotop tidak stabil
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