Complex sentence: Nitrogen is most stable when it is bonded to only three other atoms, however in the molecule nicotinamide adenine dinucleotide (NAD +), nitrogen is bonded to four other atoms, and thus has a positive formal charge.
Split into simpler sentences: Nitrogen is most stable when it is bonded to only three other atoms. However in the molecule nicotinamide adenine dinucleotide (NAD +), nitrogen is bonded to four other atoms, and thus has a positive formal charge.