In the chemical formula for water (H2O), what does the number 2 mean?

Science for Youth May 16, 2011 Print Friendly and PDF
The number 2 indicates that there are two atoms of hydrogen in a molecule of water. There is also one atom of oxygen but the number one is omitted from a chemical formula.

Connect with us

  • Twitter
  • Facebook
  • YouTube
  • Pinterest
  • Google+


This is where you can find research-based information from America's land-grant universities enabled by


Donate to Science for Youth

Your donation keeps eXtension growing.

Give Now