Final answer:
A nitrogen atom can covalently bond to three hydrogen atoms to form NH₃ (ammonia) and maintain a neutral charge because it has five valence electrons, three of which can pair with the single electron from each hydrogen.
Step-by-step explanation:
Nitrogen, which is in group 15 of the periodic table, has five valence electrons. Three of these electrons are unpaired, ready to form bonds. In the case of forming ammonia (NH₃), nitrogen shares three bonding pairs of electrons with three hydrogen atoms, each providing one electron for the bond. Since hydrogen has one valence electron and requires a duo, not an octet, to be stable, it can form only one bond. Therefore, nitrogen can covalently bond to three hydrogens and still have a neutral electrical charge.
Each hydrogen atom is then assigned one electron from the shared pair, which is the bonding pair, with no nonbonding electrons. For nitrogen, after forming three covalent bonds, it is left with one lone pair of electrons and three shared pairs with the hydrogen atoms, which satisfies the octet rule for nitrogen, thereby achieving a stable electronic configuration with a neutral charge, as well as the full valence shell of hydrogen.