Question

what ion do acids release in solution?
o hydrogen
o hydroxide
o carbonate
o ammonium

Explanation:

Acids are defined as substances that release hydrogen ions ($H^+$) in solution according to the Arrhenius theory. Hydroxide ions are released by bases, carbonate ions are related to carbonates and bicarbonates, and ammonium ions are related to ammonium - containing compounds.

Answer:

A. hydrogen