Here's why:

* Ionic Compound: Ammonium sulfate is an ionic compound, meaning it's composed of positively charged ammonium ions (NH₄⁺) and negatively charged sulfate ions (SO₄²⁻).

* Polar Solvent: Water is a polar solvent, meaning it has a positive and negative end due to the uneven sharing of electrons. This polarity allows water molecules to surround and interact with the ions of ammonium sulfate, breaking the ionic bonds and pulling the compound apart.

* Solubility: The strong attraction between water molecules and the ions of ammonium sulfate overcomes the attraction between the ions themselves, leading to its dissolution.

Ammonium sulfate is actually quite soluble in water, especially at higher temperatures.