Group ions contain two or more atoms and usually have a negative charge. The formulae of these ions can be found in the data booklet. We can take the number of charges on the ion as the valency of the ...

For example, magnesium oxide is made up of two elements, magnesium and oxygen. Its formula is MgO. This shows that it has one atom of magnesium for every one atom of oxygen.

Update regulation to spur research into drugs that the body absorbs more easily and that could reach market more quickly, urge Julia L. Shamshina and colleagues. A new realm of potential drugs is ...