Final answer:
An Arrhenius acid is a substance that increases the concentration of H+ ions in an aqueous solution, which are often represented as hydronium ions (H3O+), as introduced by Svante Arrhenius in 1884.
Step-by-step explanation:
According to the Arrhenius acid definition, an Arrhenius acid is a substance that, when dissolved in water, increases the concentration of hydrogen ions (H+) in the solution. These H+ ions are actually more properly represented by hydronium ions (H3O+) as they readily associate with water molecules. This concept was introduced by the Swedish chemist Svante Arrhenius in 1884 and is a fundamental aspect of acid-base chemistry. Classic examples of Arrhenius acids include hydrochloric acid (HCl), sulfuric acid (H2SO4), and nitric acid (HNO3), all of which release H+ ions into an aqueous solution.