Here's why:

* Ammonium (NH₄⁺) has a +1 charge.

* Chloride (Cl⁻) has a -1 charge.

To balance the charges, you need one ammonium ion (NH₄⁺) for every one chloride ion (Cl⁻).

Therefore, the correct formula for ammonium chloride is NH₄Cl.

There is no specific name for a nonexistent compound like NH₄Cl₂.