From Na2S and MgSO4 which can be considered as chalcogenides elements. And Sulphates (SO4-) are chalcogenides?

From Na2S and MgSO4 which can be considered as chalcogenides elements. And Sulphates like FeSO4, CaSO4,etc. (SO4-) are chalcogenides?

19 January 2016 5,834 7 View