Symbol	Si
Atomnummer	14
Gruppe	14 ( Kulstof-silicium-gruppe)
Periode	3
Blok	p
Klassifikation	Halvmetal

Udseende	Crystalline, reflective with bluish-tinged faces
Farve	Grå

Antal protoner	14 p+
Antal neutroner	14 n0
Antal elektroner	14 e-

Fra Wikipedia, den gratis encyklopædiSilicium, på dansk også kaldet kisel, er grundstoffet med atomnummeret 14 og symbolet Si. Det tetravalente halvmetal silicium er mindre reaktivt end dets kemiske analog carbon. Selvom det er det 8. mest almindelige grundstof i universet efter masse, så fremkommer det kun af og til som et rent grundstof i naturen, men er mere fordelt i støv og planter i form af siliciumdioxid eller silikat. På Jorden er silicium det næstmest forekommende stof (efter ilt) i jordskorpen. Jordskorpen består af 27,2% silicium efter masse.

Fase ved STP	Fast
Massefylde	2.329 g/cm3
Atommasse	28.084 u

Smeltepunkt	1687 K 1413.85 °C 2576.93 °F
Kogepunkt	3538 K 3264.85 °C 5908.73 °F
Fordampningsvarme	359 kJ/mol

Elektronegativitet (Pauling Scale)	1.9
Elektronaffinitet	134.068 kJ/mol
Oxidationstrin	−4, −3, −2, −1, 0, +1, +2, +3, +4 (an amphoteric oxide)
Ioniseringsenergier	786.5 kJ/mol 1577.1 kJ/mol 3231.6 kJ/mol 4355.5 kJ/mol 16091 kJ/mol 19805 kJ/mol 23780 kJ/mol 29287 kJ/mol 33878 kJ/mol 38726 kJ/mol 45962 kJ/mol 50502 kJ/mol 235196 kJ/mol 257923 kJ/mol

Elektronkonfiguration Kortfattet konfiguration	[Ne] 3s2 3p2
Elektronkonfiguration Fuld konfiguration	1s2 2s2 2p6 3s2 3p2
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p2
Elektroner pr. Skal	2, 8, 4
Valenselektroner	4
Valency-elektroner	4
Bohrs atommodel	Figur: Skaldiagram af Silicium (Si) atom.
Orbital diagram	1s 2s 2p 3s 3p

Forudsigelse	Antoine Lavoisier (1787)
Opdagelse og første isolation	Jöns Jacob Berzelius (1823)
Navngivet af	Thomas Thomson (chemist) (1817)
Opdagelse af silicium In 1787, Antoine Lavoisier suspected that silica might be an oxide of a fundamental chemical element. After an attempt to isolate silicon in 1808, Sir Humphry Davy proposed the name "silicium" for silicon. Gay-Lussac and Thénard are thought to have prepared impure amorphous silicon in 1811, through the heating of recently isolated potassium metal with silicon tetrafluoride, but they did not purify and characterize the product, nor identify it as a new element. Silicon was given its present name in 1817 by Scottish chemist Thomas Thomson. He retained part of Davy's name but added "-on" because he believed that silicon was a nonmetal similar to boron and carbon. In 1824, Jöns Jacob Berzelius prepared amorphous silicon using approximately the same method as Gay-Lussac (reducing potassium fluorosilicate with molten potassium metal), but purifying the product to a brown powder by repeatedly washing it. As a result, he is usually given credit for the element's discovery.

CAS Number	7440-21-3
ChemSpider ID	4574465
EC number	231-130-8
PubChem CID Number	5461123