The molecule NH3 represents ammonia. It consists of one nitrogen atom (N) and three hydrogen atoms (H) bonded together. To calculate the total number of atoms in 4 molecules of NH3, you can break it down as follows:
4 molecules x (1 nitrogen atom + 3 hydrogen atoms) = 4 molecules x 4 atoms = 16 atoms
So, there are a total of 16 atoms in 4 molecules of NH3.