Concept:Ammonium ion is formed when ammonia shares its lone pair of electrons with a hydrogen ion.
This sharing of an electron pair is a type of covalent bond.
Explanation:Ammonia,
NH3, has a lone pair of electrons on its nitrogen atom.
A hydrogen ion,
H+, has no electrons of its own.
The nitrogen atom donates its lone pair to the hydrogen ion.
Since both shared electrons come from the same atom, the bond is called a dative covalent bond.
A dative covalent bond is still a form of covalent bond.
Hence, the bond formed in
NH4+ is covalent in nature.
Answer:D. covalent bond