[Technicalhuman]

It is said that magnesium oxide is not soluble with water. However, aren't all metal oxides insoluble in water because they either react with the water or just remain as a solid in the water?

so why do my notes say that magnesium oxide is quite insoluble in water while aluminium oxide is even less soluble? Do they mean reactivity?

[curiouscat]

Often times soluble is taken to include react. It's really hard to define it some times.