Write a formula for the ionic compound that forms between each pair of elements.
a. silver and chlorine
b. sodium and sulfur
c. aluminum and sulfur
d. potassium and chlorine

• A. AgCl₂, Na₂S, Al₂S₃, and KCl
• B. AgCl, NaS, AlS, and KCl
• C. AgCl, NaS₂, Al₃S₂, and KCl
• D. AgCl, Na₂S, Al₂S₃, and KCl

Answer: (D)