When ammonia is reacted with HCl it abstracts proton from acid and forms Ammonium Ion and Chloride Ion.
NH₃ + HCl → ⁺NH₄ + Cl⁻ (simply Written NH₄Cl)
Structure,
The structure of Ammonium Chloride is among those structures which contains all three types of bonding's, i.e.
Ionic Bond
Covalent Bond
Coordinate Covalent Bond
Three Hydrogen atoms previously bonded with Nitrogen are covalent in nature. The new incoming proton from HCl forms co-ordinate covalent bond with Nitrogen and Chloride Ion containing negative charge make Ionic Bond with the positive Ammonium Ion. In question, if the line between Nitrogen and Chlorine atom is assumed covalent then it is incorrect. Structure is shown below,
