Question #0fc8e

1 Answer
Jul 1, 2017

3 atoms.

Explanation:

As its chemical formula suggests, a molecule of water contains

  • two atoms of hydrogen, 2 xx "H"
  • one atom of oxygen, 1 xx "O"

This means that a single molecule of water contains a total of 3 atoms.

"no. of atoms in H"_2"O" = "2 atoms of H + 1 atom of O"

"no. of atoms in H"_2"O" = "3 atoms"

![https://www.dreamstime.com/stock-photography-molecule-water-h2o-image6468242](useruploads.socratic.org)

So remember, we use subscripts to denote the number of atoms of each element present in a given compound. Keep in mind that we do not add a subscript of 1 when dealing with a single atom.

So in this case, two atoms of hydrogen are shown by adding a subscript of 2 after "H". The single atom of oxygen is shown by adding the chemical symbol of oxygen without a subscript of 1.

So instead of

"H"_2"O"_1

we have

"H"_2"O"