What is the mass percentage of carbon in a CO2 molecule?

First we need to calculate the total mass of a CO₂ molecule. This is done by summing up the individual masses of all the atoms. To find these, we look at the periodic table and see that the masses are C: 12 g/mol (amu) O: 16 g/mol (amu)Thus, the total mass of one CO₂ molecule is 12+16x2 = 44 g/mol (amu)To find the percentage, we have to divide the mass of carbon (found in the molecule) by the total mass of the molecule, and multiply by 100:%C = 12*100/44 = 27.27%