Drawing the Lewis Structure for Water

Viewing Notes:

  • Make sure you put the correct atom at the center of the Water (H2O) molecule.
  • With the Lewis Structure for Water (H2O) remember that water only needs two valence electrons to have a full outer shell.
  • Be sure that you don't use more than the eight valence electrons available.


Transcript: This is Dr. B. Let's do the Lewis structure for water: H2O. On the periodic table, Hydrogen's in group 1, it has 1 valence electron; but we have two of them, so let's multiply that by 2. And Oxygen is in group 6, sometimes called 16, so it has 6 valence electrons. So 1 times 2 is 2, plus 6; 2 plus 6 equals 8. We have a total of eight valence electrons. We'll put the Oxygen in the center, and Hydrogens always go on the outside.

And then we'll put a pair of electrons between the atoms to form chemical bonds. And Hydrogen only needs two valence electrons to have a full outer shell, so both Hydrogens have full outer shells. We've used 2, 4; so we have a total of 8. So we have 2, 4, we'll put them on the central atom, 6, 8. and now we've used all of our valence electrons. We can see Hydrogen, they both have two valence electrons, so their outer shells are full. And the Oxygen has eight valence electrons, so it has an octet and its outer shell is full.

So that's the Lewis structure for water. This is Dr. B., and thanks for watching.