Here's how to break down the number of atoms in 4HNO3:

* HNO3 represents one molecule of nitric acid.

* 4HNO3 means we have four molecules of nitric acid.

Let's count the atoms:

* Hydrogen (H): There is 1 hydrogen atom per HNO3 molecule, and we have 4 molecules, so there are 4 * 1 = 4 hydrogen atoms.

* Nitrogen (N): There is 1 nitrogen atom per HNO3 molecule, and we have 4 molecules, so there are 4 * 1 = 4 nitrogen atoms.

* Oxygen (O): There are 3 oxygen atoms per HNO3 molecule, and we have 4 molecules, so there are 4 * 3 = 12 oxygen atoms.

In summary:

* 4 hydrogen atoms (H)

* 4 nitrogen atoms (N)

* 12 oxygen atoms (O)