Ammonium sulfate contains four distinct elements

Steps:

• Recall the chemical formula of ammonium sulfate: (NH₄)₂SO₄.
• Break down the components: NH₄ provides nitrogen (N) and hydrogen (H); SO₄ provides sulfur (S) and oxygen (O).
• List unique elements: N, H, S, O.
• Count distinct elements: four total.

Why B is correct:

• The formula (NH₄)₂SO₄ includes exactly four elements—nitrogen, hydrogen, sulfur, and oxygen—as defined by its ionic structure.

Why the others are wrong:

• A: Underestimates; compound has more than two elements.
• C: Counts total atoms (two N, eight H, one S, four O), not unique elements.
• D: Overestimates with no basis in the formula.

Final answer: B