Symbol | Sr |
Atomnummer | 38 |
Gruppe | 2 (Jordalkalimetaller) |
Periode | 5 |
Blok | s |
Klassifikation | Jordalkalimetal |
Udseende | - |
Farve | Sølv |
Antal protoner | 38 p+ |
Antal neutroner | 50 n0 |
Antal elektroner | 38 e- |
Fase ved STP | Fast |
Massefylde | 2.64 g/cm3 |
Atommasse | 87.621 u |
Smeltepunkt | 1050 K 776.85 °C 1430.33 °F |
Kogepunkt | 1650 K 1376.85 °C 2510.33 °F |
Fordampningsvarme | 136.9 kJ/mol |
Elektronegativitet (Pauling Scale) | 0.95 |
Elektronaffinitet | 5.023 kJ/mol |
Oxidationstrin | +1, +2 (a strongly basic oxide) |
Ioniseringsenergier |
|
Opdaget | William Cruickshank (1787) |
Første isolation | Humphry Davy (1808) |
Opdagelse af strontium Both strontium and strontianite are named after Strontian, a village in Scotland near which the mineral was discovered in 1790 by Adair Crawford and William Cruickshank; it was identified as a new element the next year from its crimson-red flame test color. The element was eventually isolated by Sir Humphry Davy in 1808 by the electrolysis of a mixture containing strontium chloride and mercuric oxide, and announced by him in a lecture to the Royal Society on 30 June 1808. In keeping with the naming of the other alkaline earths, he changed the name to strontium. |