Final answer:
The dissociation of NH4I produces ammonium ions (NH4+) and iodide ions (I-), and these ions combine in a 1:1 ratio to form the neutral ionic compound ammonium iodide.
Step-by-step explanation:
In the dissociation of the ionic compound NH4I, the ions formed are the ammonium ion (NH4+) and the iodide ion (I-). To correctly represent the ionic charges, we should not include the charges in the formula itself, but it's important to know these when predicting the formula of the compound that forms from the union of the ions. For instance, one ammonium ion has a single positive charge, and one iodide ion has a single negative charge, so they combine in a 1:1 ratio to form NH4I, which is neutral.
The ammonium ion NH4+ is derived from the ammonia molecule (NH3) after it accepts a proton (H+), turning into a positively charged polyatomic ion. On the other hand, the iodide ion (I-) is simply an iodine atom that has gained an extra electron and carries a single negative charge. When these ions combine, they form the salt ammonium iodide.