Answer: There are 9 hydrogen atoms in the given chemical formula.
Step-by-step explanation:
We are given a chemical formula of ammonia which is

This molecule is formed by the combination of hydrogen and nitrogen atoms.
In 1 mole of ammonia, 1 atom of nitrogen is there and 3 atoms of hydrogen is there.
We are given:
Moles of ammonia = 3
So, 3 atoms of nitrogen is there and 9 atoms of hydrogen is there.
Hence, there are 9 hydrogen atoms in the given chemical formula.