It is found that 1.431 g of element X contains 7.509 × 1021 atoms. The atomic mass of X is? How many protons does it contain? A compound containing only carbon, hydrogen, and oxygen is subjected to elemental analysis. Upon complete combustion, a 0.4266-g sample of the compound produced 0.5518 g of CO2 and 0.2259 g of H2O. What is the empirical formula of the compound?