This drill tests percent composition concepts. To begin, press "New Compound" and a chemical formula will appear. Calculate the mass percentagess for all of the elements and enter them in the cells. The results and a running total will appear in the table. If you get a problem "incorrect", redo it and recheck your
answer. All masses are presented to four significant figures and percents are presented to three significant figures. Pressing "Show Answer" will display the solution and you will no longer be able submit an answer for that problem.