Here's why:
* NH₄⁺: This is the ammonium ion, a positively charged polyatomic ion consisting of one nitrogen atom and four hydrogen atoms.
* SO₄²⁻: This is the sulfate ion, a negatively charged polyatomic ion consisting of one sulfur atom and four oxygen atoms.
The compound is formed by the electrostatic attraction between two ammonium ions (NH₄⁺) and one sulfate ion (SO₄²⁻).
