To calculate the formal charge of the nitrogen atom in the ammonium ion NH4+ , we can use the following formula:Formal charge = Valence electrons of the atom - Non-bonding electrons - 1/2 * Bonding electrons For nitrogen, the number of valence electrons is 5. In the ammonium ion, nitrogen is bonded to four hydrogen atoms, and each bond consists of 2 electrons 1 from nitrogen and 1 from hydrogen . There are no non-bonding electrons on nitrogen in this case, as all of its valence electrons are involved in bonding.Now, let's plug these values into the formula:Formal charge = 5 - 0 - 1/2 * 8 Formal charge = 5 - 0 - 4Formal charge = +1So, the formal charge of the nitrogen atom in the ammonium ion NH4+ is +1. This is consistent with the overall charge of the ion, which is also +1.