Naming Ionic Compounds: Before we begin, lets note a couple of things. Metals are to the left of the staircase on the Periodic Table. Nonmetals are to the right of the staircase on the Periodic Table. Polyatomic ions are ions consisting of two or more elements. The names, formulas and charges of polyatomic ions are usually needed to be memorized for the test. List of most common Polyatomic Ions: There are several types of ionic compounds. Metal + Nonmetal Name of Metal + Name