This page presents analytical data from which you are to determine the mass % composition for a compound of up to four elements. To begin, press "New Compound" and a description of a compound with its analytical data will be presented. Enter the mass %s into the cells and press "Check Answer." You should determine the values to 3 signifcant figures. The results of the problem and a running total will appear in the table. Pressing "Show Answer" will display the solution and you will no longer be able to submit an answer for that problem.