Selenium (Se)

General Properties

Symbol Se
Atomic Number 34
Atomic Weight 78.96
Group
16 (oxygen family)
VIB (IUPAC), VIA (CAS)
Solid, Diamagnetic, Stable, Natural, Nonmetal
Period 4
Block p

Physical Properties

Density 4.79 g/cm3
Atomic Volume 16.5 cm3/mole
Atomic Radius 1.4 angstroms
Covalent Radius 116 pm
Crust Abundance 5E-6%
Crystal Structure Hexagonal
Color Gray

Energy

Electronegativity 2.6 (Pauling Scale)
Electron Affinity 195 kJ/mol
1st Ionization Energy 941 kJ/mol
2nd Ionization Energy 2045 kJ/mol
3rd Ionization Energy 2973.7 kJ/mol
4th Ionization Energy 4144 kJ/mol
5th Ionization Energy 6590 kJ/mol
6th Ionization Energy 7880 kJ/mol
7th Ionization Energy 14990 kJ/mol
Specific Heat Capacity 0.32 J g−1 K−1
Thermal Conductivity 2.04 W·m−1·K−1

Electrons & Oxidation

Oxidation States +4,-2,+6
Electrons Per Shell 2 8 18 6
Electron Configuration [Ar] 4s2 3d10 4p4
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4
Orbital Diagram
1s
↿⇂
2s
↿⇂
2p
↿⇂
↿⇂
↿⇂
3s
↿⇂
3p
↿⇂
↿⇂
↿⇂
3d
↿⇂
↿⇂
↿⇂
↿⇂
↿⇂
4s
↿⇂
4p
↿⇂
↿ 
↿ 
4d
 
 
 
 
 
4f
 
 
 
 
 
 
 

Nuclear

Radioactive No

Media

Planetary Bohr Model of Selenium (Se)
Lewis Dot Diagram of Selenium (Se)
Description
Soft metalloid similar to sulfur. Ranges from gray metallic to red glassy appearance.
Uses
Light causes it to conduct electricity more easily. It is used in photoelectric cells, TV cameras, xerography machines and as a semiconductor in solar batteries and rectifiers. Also colors glass red.
Sources
Obtained from lead, copper and nickel refining. Conducts electricity when struck by light.
Pronounciation (English)
si-LEE-ni-em

Translations

Afrikaans Selenium
Aragonese Selenio
العربية سيلينيوم
Armãneashte Selenuu
asturianu Seleniu
azərbaycan dili Selen
български Селен
বাংলা সেলেনিয়াম
brezhoneg Seleniom
bosanski Selen
Byelorussian Селен
Cebuano Selenio
čeština Selen
Chuvash Селен
Cymraeg Seleni
dansk Selen
Deutsch Selen
Ελληνικά Σεληνιο
English Selenium
esperanto Seleno
español Selenio
eesti Seleen
euskara Selenioa
فارسی سلنیم
suomi Seleeni
føroyskt Selen
français Sélénium
furlan Seleni
West-Frysk Selenium
Gaeilge Seiléiniam
Gàidhlig Seilèiniam
galego Selenio
ગુજરાતી સેલેનિયમનો
Gaelg Shellainium
Hakka Chinese Sî (硒)
עברית סלניום
हिन्दी सेलेनियम
hrvatski Selenij
magyar Szelén
հայերեն Սելեն
Indonesia Selenium
íslenska Selen
italiano Selenio
日本語 セレン
ქართული სელენი
کٲشُر Selén
қазақ тілі Селен
한국어 셀렌, 2셀레늄
Kurdish Selenyûm
Komi Селен
kernewek Selenyum
кыргызча Селен
Latin Selenium
Lëtzebuergesch Selen
Lombard Seléni
lingála Seleni
lietuvių Selenas
latviešu Selēns
Mari Селен
Maori Selenium
македонски Селен
മലയാളം സെലീനിയം
монгол Селен
Мокшан Селени
Bahasa Melayu Selenium
Malti Selinju[m]
Nahuatl Selenio
Nederlands Selenium
norsk Selen
Occitan Selèni
ирон Селен
polski Selen
português Selénio
Runasimi Silinyu
română Seleniu
русский Селен
slovenčina Selén
slovenščina Selen
Samoan Selenimi
Samogitian Selens
shqip Selen
српски Селен
Southern Sotho Seleniamo
svenska Selen
Kiswahili Seleni
தமிழ் செலெனியம்
Tajik Селен
ไทย ซีลีเนียม
Türkçe Selenyum
ئۇيغۇرچە سېلېن
українська Селен
o‘zbek Selen
Tiếng Việt Selen
Võro Seleen
中文

History

Discovered In
1817
Discovered By
Jöns Berzelius
Discovered At
Sweden
Word Origin
From the Greek word "selene" meaning "moon"