Find the element’s group on the periodic table
Metals usually lose electrons and form positive ions
Nonmetals usually gain electrons and form negative ions
Group 1 elements form 1+ ions
Group 2 elements form 2+ ions
Group 13 elements form 3+ ions
Group 15 elements form 3- ions
Group 16 elements form 2- ions
Group 17 elements form 1- ions
Group 18 elements usually form no ions
Transition metals can have multiple charges
Use Roman numerals in names to identify transition metal charge
Monatomic ion charge equals the number of electrons lost or gained
Polyatomic ions have fixed charges
Check common ion charge charts when needed