Try Ca(NO 3 ) 2 How many Ca How many Ca How many NO 3 How many NO 3 How many N How many N How many O How many O 1 Ca (1x1) 1 Ca (1x1) 2 NO 3 (1X2) 2 NO 3 (1X2) 2 N (1x2x1) 2 N (1x2x1) 6 O (1x2x3) 6 O (1x2x3) Try 2Ca(NO 3 ) 2 How many Ca How many Ca How many NO 3 How many NO 3 How many N How many N How many O How many O 2 Ca (2X1) 2 Ca (2X1) 4 NO 3 (2x2) 4 NO 3 (2x2) 4 N (2x2x1) 4 N (2x2x1) 12 O (2x2x3) 12 O (2x2x3)