Here's how to determine the number of atoms in a molecule of nitric acid (HNO₃):

* HNO₃ represents the chemical formula for nitric acid.

* H stands for one hydrogen atom.

* N stands for one nitrogen atom.

* O₃ stands for three oxygen atoms.

Therefore, a molecule of nitric acid contains a total of 5 atoms (1 + 1 + 3 = 5).