Lewis Theory Predicts the Correct Chemical Formulas for Ionic Compounds

Consider the ionic compound formed between sodium and sulfur.

• The Lewis structures for sodium and sulfur are as follows:
• Sodium must lose one valence electron to obtain an octet (in the previous principal shell), while sulfur must gain two electrons to obtain an octet.
• The compound that forms between sodium and sulfur requires
• two sodium atoms to every one sulfur atom. The Lewis structure is
• as follows:
• The correct chemical formula is Na2S.