Селен
34
Se
Група
16
Периода
4
Блок
p
Протони
Електрони
Неутрони
34
34
45
Општа својства
Атомски број
34
Атомска маса
78,96
Масени број
79
Категорија
Други неметали
Боја
Сива
Радиоактиван
Не
From the Greek word Selene, moon
Кристална структура
Проста Моноклинска
Историја
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.
Електрони по љусци
2, 8, 18, 6
Електронска конфигурација
[Ar] 3d10 4s2 4p4
Selenium deficiency in animals can lead to slow growth
Физичка својства
Стање
Чвсрто
Густина
4,809 g/cm3
Температура топљења
494,15 K | 221 °C | 429,8 °F
Температура кључања
958,15 K | 685 °C | 1265 °F
Топлота топљења
5,4 kJ/mol
Топлота испаравања
26 kJ/mol
Специфична топлота
0,321 J/g·K
Заступљеност у Земљиној кори
5×10-6%
Заступљеност у Космосу
3×10-6%
CAS број
7782-49-2
ПубЦхем ЦИД број
6326970
Атомска својства
Атомски радијус
120 pm
Ковалентни радијус
120 pm
Електронегативност
2,55 (Полингова скала)
Јонизујући потенцијал
9,7524 eV
Молска запремина
16,45 cm3/mol
Топлотна проводљивост
0,0204 W/cm·K
Оксидациона стања
-2, 2, 4, 6
Примена
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
Изотопи
Стабилни изотопи
74Se, 76Se, 77Se, 78Se, 80SeНестабилни изотопи
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