Tecken | Si |
Atomnummer | 14 |
Grupp | 14 (Kolgruppen) |
Period | 3 |
Block | p |
Ämnesklass | Halvmetall |
Utseende | Crystalline, reflective with bluish-tinged faces |
Färg | Grå |
Antal protoner | 14 p+ |
Antal neutroner | 14 n0 |
Antal elektroner | 14 e- |
Fas vid STP | Fast |
Densitet | 2.329 g/cm3 |
Relativ atommassa | 28.084 u |
Smältpunkt | 1687 K 1413.85 °C 2576.93 °F |
Kokpunkt | 3538 K 3264.85 °C 5908.73 °F |
Ångbildningsvärme | 359 kJ/mol |
Elektronegativitet (Paulingskalan) | 1.9 |
Elektronaffinitet | 134.068 kJ/mol |
Oxidationstal | −4, −3, −2, −1, 0, +1, +2, +3, +4 (an amphoteric oxide) |
Jonisationspotential |
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Förutsägelse | Antoine Lavoisier (1787) |
Upptäckt och första isolation | Jöns Jacob Berzelius (1823) |
Namngivare | Thomas Thomson (chemist) (1817) |
Upptäckten av kisel 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. |