The total number of atoms in the ammonia is four.
Step-by-step explanation:
The chemical formula for ammonia is
which has one atom of nitrogen with 3 atoms of hydrogen. The number of atom is counted from the chemical formula itself.
As there is one N shown so there will be one atom of nitrogen. Then there is H is shown with 3 subscript, so there is 3 atom of hydrogen. Therefore,
1 atom of nitrogen + 3 atom of hydrogen = 4 atoms in ammonia.