The question is a bit tricky! It seems like there might be a typo. Here's why:

* 3NH3 represents three molecules of ammonia (NH3).

* One molecule of ammonia (NH3) has 1 nitrogen atom (N) and 3 hydrogen atoms (H), totaling 4 atoms.

Therefore, the number of atoms in three molecules of ammonia (3NH3) is:

* 4 atoms per molecule * 3 molecules = 12 atoms

Let me know if you had a different question in mind!