Oxygen and sulfur have 6 valence electrons because they are in group 6A, and barium has 2 valence electrons because it is in group 2A. The group number indicates the number of valence electrons. B)Based on the number of valence electrons, indicate the monatomic ion (symbol with charge) each
element will form.

c)Sulfur and oxygen can covalently bond to form a polyatomic ion. Write the formula of a polyatomic
ion that phosphorus and oxygen make. Make sure to include the ion charge.

d. Using the monatomic ions you listed above in (b), the polyatomic ion from (c), and what you have
learned in the unit, write the formulas for the three ionic compounds these ions would form.