Since the given formula is . According to cross method formula, magnesium has +2 charge so, is multiplied by 2. Thus, 1 molecule of magnesium phosphate will contain 2 atoms of phosphorus. Therefore, three molecules of magnesium phosphate contains following number of atoms. Mg = 9 P = 6 O = 24 Hence, we can conclude that there are 6 atoms of phosphorus in three molecules of magnesium phosphate, .
