What is noticeable about all of the ionic charges in Group 1 2 15 16 and 17?

The ionic charges of group 1 and 2 metals are +1 and +2 respectively. Group 15 & 16 the simple mono-atomic ions are -3 and -2. Group 17 ions are -1. This can be explained by the following elemnts in groups 1 and 2 lose 1 or 2 electrons respectively to achieve a noble gas configuration whereas groups 15, 16 and 17 gain electrons (3,2 1 respectively)