Skip to main content
U.S. flag

An official website of the United States government

Water Isotopes Diagram

November 2015 (approx.)

Detailed Description

Water isotopes refer to atoms of oxygen (O) and hydrogen (H) in water molecules (H2O) that have slightly different atomic masses due to different numbers of neutrons in their nucleus. Water is composed of one oxygen and two hydrogen atoms and the different combinations of their stable isotopes have molecular masses that range from 18 to 22.


Public Domain.