This is a generalization and there are exceptions to this rule lead for example is a main group element but can take on +2 and +4 charges.Įlements in the middle of the periodic table, the transition metals, can take on several different positive charges in different compounds. Group 1 elements have 1+ charges for example, while group 17 elements have 1- charges.

The elements in the s and p blocks (groups 1,2, & 13-18) are collectively referred to as main group and for the most part have constant charges. So the cumulative charges of the cations (a metal often) must equal the charges of the anions (a nonmetal often). The positive charges must equal and cancel all the negative charges. Ionic compound’s empirical formulae always have a neutral net charge, or a total charge of 0. The elements in the middle of the periodic table, the transition metals, are odd in that they have the potential of taking on several possible positive charges. And the groups further to the right tend to take on negative charges to become anions because they like to accept electrons now instead of donate them.Ĭollectively these elements in groups 1-2 & 13-18 are known as main block elements and have (usually) constant charges. Elements in group 14 have the possibility of taking on a +4 or a -4 charge. Elements in group 13 take on a +3 charge. Elements in group 2, the alkaline earth metals, take on a +2 charge for a similar reason. Elements in group 1, the alkali metals, have one valence electrons so they tend to lose that one electron and take on a +1 charge. It corresponds to how many valence electrons those elements in that group have and therefore how many they wish to donate to other atoms to form cations. For the most part it depends on the group (column) in which the element is found in on the periodic table.

Periodic table with charges ions