The elements that form ions with a -3 charge are primarily nonmetals, specifically those in Group 15 (also known as Group 5A) of the periodic table. These elements are:

* Nitrogen (N): Forms the nitride ion (N³⁻)

* Phosphorus (P): Forms the phosphide ion (P³⁻)

* Arsenic (As): Forms the arsenide ion (As³⁻)

* Antimony (Sb): Forms the antimonide ion (Sb³⁻)

* Bismuth (Bi): Forms the bismuthide ion (Bi³⁻)

Note: While these elements typically form -3 ions, they can sometimes form other ions depending on the chemical environment.