The formal charge of the nitrogen atom in the molecule NH3 ammonia can be calculated using the following formula:Formal charge = Valence electrons of the atom - Non-bonding electrons - 1/2 x Bonding electrons For nitrogen in NH3:1. Valence electrons of nitrogen = 5 as nitrogen is in group 15 of the periodic table 2. Non-bonding electrons = 2 there is one lone pair on nitrogen 3. Bonding electrons = 6 as there are three single bonds between nitrogen and three hydrogen atoms, each bond has 2 electrons Now, we can calculate the formal charge:Formal charge = 5 - 2 - 1/2 x 6 Formal charge = 5 - 2 - 3Formal charge = 0So, the formal charge of the nitrogen atom in NH3 is 0.