How many atoms are present in a single molecule of water (H2O)?

A single molecule of water, represented chemically as H2O, contains three atoms in total. This composition breaks down into two hydrogen atoms and one oxygen atom. The formula shows that for every molecule of water, there are specifically two hydrogen (H) atoms and one oxygen (O) atom combined to form the molecule. Therefore, when counting the total number of atoms, you add these together: 2 (from hydrogen) + 1 (from oxygen) equals 3 atoms in total.

Understanding the molecular structure of water is fundamental in chemistry and underscores the importance of recognizing how atoms combine to form different substances. This foundational knowledge is critical for grasping more complex chemical concepts.