If you look at the handy periodic table, you can look up the mass for each of these. Hydrogen is about 1 while oxygen is about 16. There are two ways of looking at this. As an individual molecule, it would weigh 18 atomic mass units (amu). However, that is not feasible to weigh on a scale. read more
From the formula, you can see that water consists of two hydrogen atoms and one oxygen atom per molecule. If you look at the handy periodic table, you can look up the mass for each of these. Hydrogen is about 1 while oxygen is about 16. There are two ways of looking at this. As an individual molecule, it would weigh 18 atomic mass units (amu). read more
In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together. read more