The relation between molecular (formula) mass and molar mass Page 4 4 • To obtain one mole of copper atoms (6.02 x 1023 atoms), weigh out 63.55 g copper. The molar mass (M) of a substance is the mass of one mole of entities (atoms, molecules, or formula units) of the substance.
Water is H2O, whereas Hydrogen Peroxide is H2O2 -> the extra oxygen atom changes the substance entirely.
This has all of the charges above the columns. Hopefully it helps!
