Selen

34
Se
Guruh
16
Davr
4
Block
p
Protonlar
Elektronlar
Neytronlar
34
34
45
General Properties
Atom raqami
34
Atom massasi
78,96
Mass Number
79
Turkum
Qolgan metallmaslar
Ranggi
Gray
Radioaktivlik
Yoʻq
From the Greek word Selene, moon
Crystal Structure
Simple Monoclinic
Tarix
Selenium was first observed in about the year 1300 by the alchemist Arnold of Villanova.

Selenium was discovered in 1817 by Jöns Jacob Berzelius and Johan Gottlieb Gahn who noted the similarity of the new element to the previously-known tellurium.

In 1873, Willoughby Smith found that the electrical resistance of grey selenium was dependent on the ambient light.
Electrons per shell
2, 8, 18, 6
Elektron konfiguratsiyasi
[Ar] 3d10 4s2 4p4
Se
Selenium deficiency in animals can lead to slow growth
Physical Properties
Phase
Qattiq modda
Zichlik
4,809 g/cm3
Erish harorati
494,15 K | 221 °C | 429,8 °F
Qaynash harorati
958,15 K | 685 °C | 1265 °F
Heat of Fusion
5,4 kJ/mol
Heat of Vaporization
26 kJ/mol
Solishtirma issiqlik sigʻimi
0,321 J/g·K
Abundance in Earth's crust
5×10-6%
Abundance in Universe
3×10-6%
Ultrapure
Image Credits: Images-of-elements
Ultrapure black, amorphous selenium
CAS Number
7782-49-2
PubChem CID Number
6326970
Atomic Properties
Atom radiusi
120 pm
Kovalentlik radiusi
120 pm
Elektrmanfiylik
2,55 (Poling boʻyicha)
Ionization Potential
9,7524 eV
Molyar hajm
16,45 cm3/mol
Issiqlik oʻtkazuvchanlik
0,0204 W/cm·K
Oksidlanish darajasi
-2, 2, 4, 6
Applications
Selenium is used in the glass industry to decolorize glass and to make red-colored glasses and enamels.

It is used as a catalyst in many chemical reactions.

It is also used as a photographic toner, and as an additive to stainless steel.

Selenium sulfide is used in anti-dandruff shampoos.
Many of selenium's compounds, such as selenates and selenites, are highly toxic
Izotoplar
Barqaror izotoplar
74Se, 76Se, 77Se, 78Se, 80Se
Beqaror izotoplar
65Se, 66Se, 67Se, 68Se, 69Se, 70Se, 71Se, 72Se, 73Se, 75Se, 79Se, 81Se, 82Se, 83Se, 84Se, 85Se, 86Se, 87Se, 88Se, 89Se, 90Se, 91Se, 92Se, 93Se, 94Se