The strength of attraction for a metal ion is dependent on several factors. The ionic charge can be determined by how many valence electrons it donated and the element's position on the periodic table. It is more common to have a lower ionic charge than a higher ionic charge.
The amount of valence electrons that a metallic element donates is different depending on the group to which it belongs. For example, with the exception of hydrogen, which is a nonmetal, elements in Groups 1 and 2 have 1 and 2 valence electrons respectively available for donating. Transition metals, which are found in Groups 3 through 12, can have a wide range of oxidation states and donate different numbers of valence electrons depending on the conditions present and the elements with which they are interacting. There are certain patterns established, however, and many transition metals are commonly only found in one or two of their possible oxidation states.
Valence electrons are the foundation for atomic bonding and intermolecular forces. If valence electrons are donated or received, they lead to ionic bonding. If they are shared, valence electrons help form covalent bonds. Metal ions are more commonly found in ionic bonds with nonmetal ions although they can form metallic bonds with each other.