Seleen
34
Se
Groep
16
Periode
4
Blok
p
Protonen
Elektronen
Neutronen
34
34
45
Algemene Eigenschappen
Atoomnummer
34
Atomair gewicht
78,96
Massa Getal
79
Categorie
Niet-metalen
Kleur
Grijs
Radioactief
Nee
Van het Griekse woord selene, maan
Kristalstructuur
Eenvoudig Monoklien
Historie
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.
Eletronen per schil
2, 8, 18, 6
Electronconfiguratie
[Ar] 3d10 4s2 4p4
Selenium deficiency in animals can lead to slow growth
Fysieke Eigenschappen
Fase
Vast
Dichtheid
4,809 g/cm3
Smeltpunt
494,15 K | 221 °C | 429,8 °F
Kookpunt
958,15 K | 685 °C | 1265 °F
Fusiewarmte
5,4 kJ/mol
Verdampingswarmte
26 kJ/mol
Specifieke Warmtecapaciteit
0,321 J/g·K
Overvloedig aanwezig in de aardkorst
5×10-6%
Overvloedig aanwezig in het universum
3×10-6%
CAS-nummer
7782-49-2
PubChem CID nummer
6326970
Atoomeigenschappen
Atoomstraal
120 pm
Covalentiestraal
120 pm
Electronegativiteit
2,55 (Pauling schaal)
Ionisatiepotentiaal
9,7524 eV
Atoomvolume
16,45 cm3/mol
Thermische geleiding
0,0204 W/cm·K
Oxidatietoestanden
-2, 2, 4, 6
Toepassingen
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
Isotopen
Stabiele isotopen
74Se, 76Se, 77Se, 78Se, 80SeInstabiele isotopen
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