Selen
34
Se
Grupa
16
Okres
4
Blok
p
Protony
Elektrony
Neutrony
34
34
45
Ogólne właściwości
Liczba atomowa
34
Masa atomowa
78,96
Liczba masowa
79
Kategoria
Niemetale
Kolor
Szary
Radioaktywny
Nie
From the Greek word Selene, moon
Układ krystalograficzny
Jednoskośny prosty
Historia
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.
Elektrony na poszczególnych powłokach
2, 8, 18, 6
Konfiguracja elektronowa
[Ar] 3d10 4s2 4p4
Selenium deficiency in animals can lead to slow growth
Właściwości fizyczne
Stan skupienia
Ciało stałe
Gęstość
4,809 g/cm3
Temperatura topnienia
494,15 K | 221 °C | 429,8 °F
Temperatura wrzenia
958,15 K | 685 °C | 1265 °F
Ciepło topnienia
5,4 kJ/mol
Ciepło parowania
26 kJ/mol
Ciepło właściwe
0,321 J/g·K
Ilość w skorupie Ziemi
5×10-6%
Ilość we Wszechświecie
3×10-6%
Numer CAS
7782-49-2
Numer CID PubChem
6326970
Właściwości atomowe
Promień atomowy
120 pm
Promień walencyjny
120 pm
Elektroujemność
2,55 (Skali Paulinga)
Energia jonizacji
9,7524 eV
Objętość molowa
16,45 cm3/mol
Przewodność cieplna
0,0204 W/cm·K
Stopnie utlenienia
-2, 2, 4, 6
Zastosowania
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
Izotopy
Stabilne izotopy
74Se, 76Se, 77Se, 78Se, 80SeNiestabilne izotopy
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