Question

How many atoms are in one water molecule?

Answer 1

To count atoms in a molecule, add the subscripts of the molecule. Remember that if you do not see a subscript after a symbol, its subscript is 1. One molecule of water contains 3 atoms.

Explanation:

The molecular formula for water is `H_2O`, meaning there are 2 hydrogen atoms and one oxygen atom. I found this by adding the subscripts. 2 is the subscript on hydrogen, and 1 is the subscript on oxygen, so 2 + 1 = 3 atoms total.

For example, to count the number of atoms in one molecule of glucose, `C_6H_12O_6`, add the subscripts, so 6+12+6 is 24 atoms. Note that `C_6H_12O_6` is the molecular formula of glucose, not the empirical formula.