a. How many ATOMS of silicon are present in 3.88grams of silicon dioxide? atoms of silicon . b. How many GRAMS of oxygen are present in 3.381022 molecules of silicon dioxide? grams of oxygen. Use the References to acce The percent by mass of chlorine in B5H8Cl is %. (Enter your answer to four significant figures.) 1. How many grams of Na+are present in 4.71 grams of sodium chromate? grams Na+. 2. How many grams of sodium chromate contain 1.45 grams of Na+? grams sodium chromate. According to the following reaction, how many grams of ammonia will be formed upon the complete reaction of 21.0 grams of hydrogen gas with excess nitrogi Massanitrogen(g)+hydrogen(9)ammonia(g)gramsammonia