Introduction: Chemical formulas represent ratios. To make H2O, you need two atoms of H for each atom of O; you would also need two moles of H for every mole of O. However, when performing experiments in the lab, substances are measured in grams, not atoms or moles. Therefore, it is important to be able to convert freely between atoms, moles, and grams. Question: How do you convert particles to grams, and grams to particles