Write the empirical (or molecular) formulas of compounds that these elements in the third period are expected to form with molecular oxygen and molecular chlorine. (If different oxidation states are possible for an element, write the formula for a highest oxidation state.) In each case indicate whether you expect the compound to be ionic or molecular. Element: Compound formed with oxygen: Formula Ionic or molecular? Na Mg Al Si P S Element: Compound formed with chlorine: Formula Ionic or molecular? Na Mg Si P