What is an ion charge

Chemistry for career changers - Volume 4 - Ions / Ions: spatially undirected binding capacity
7.1 Standard charges of the ions

Just as the number of directional binding capacities on a non-metal atom can vary, so do the ions with different ion charges. Here, too, we can orientate ourselves based on the position of the ions in the main groups. The following rules apply to them:

Rule 1: The ion charge of the positive ions corresponds to the main group number: calcium ions or magnesium ions (2nd main group), for example, have a charge of 2+, aluminum ions (3rd main group) have a charge of 3+.

Rule 2: The charge numbers of the negative ions correspond to the number of main groups reduced by 8: chloride ions (7th main group) are characterized by the charge number 7 - 8 = -1, sulfide ions (6th main group) by the charge number 6 - 8 = -2 .

Metal ions are consistently located in the subgroups. Most ions have a charge number of 2+, but the ion charge can also be varied. The maximum ion charge is given by the number of subgroups, as a rule for the ions of the subgroups has proven itself:

Rule 3: Metal ions of the subgroups mostly occur with a charge number of 2+. Frequently occurring ions are also: Ag +, Cr3 +, Fe3 +, Ti4 +.

With these three rules approx. 90% of the ion compounds common in practice can be described.