Selen
34
Se
Skupina
16
Perioda
4
Blok
p
Protoni
Elektroni
Nevtroni
34
34
45
Splošne lastnosti
Vrstno število
34
Atomska teža
78,96
Masno število
79
Kategorija
Druge nekovine
Barva
Siva
Radioaktivno
Ne
From the Greek word Selene, moon
Kristalna struktura
Primitivna monolinska
Zgodovina
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.
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.
Elektroni po lupinah
2, 8, 18, 6
Razporeditev elektronov
[Ar] 3d10 4s2 4p4
Selenium deficiency in animals can lead to slow growth
Fizikalne lastnosti
Faza snovi
Trdnina
Gostota
4,809 g/cm3
Tališče
494,15 K | 221 °C | 429,8 °F
Vrelišče
958,15 K | 685 °C | 1265 °F
Talilna toplota
5,4 kJ/mol
Izparilna toplota
26 kJ/mol
Toplotna kapaciteta
0,321 J/g·K
Zastopanost v Zemljini skorji
5×10-6%
Zastopanost v vesolju
3×10-6%
CAS številka
7782-49-2
PubChem CID številka
6326970
Atomske lastnosti
Atomski polmer
120 pm
Kovalentni polmer
120 pm
Elektronegativnost
2,55 (Paulingova lestvica)
Ionizacijski potencial
9,7524 eV
Atomski volumen
16,45 cm3/mol
Toplotna prevodnost
0,0204 W/cm·K
Oksidacijska stanja
-2, 2, 4, 6
Uporabe
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.
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
Izotopi
Stabilni izotopi
74Se, 76Se, 77Se, 78Se, 80SeNestabilni izotopi
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