What characteristic property did arrhenius attribute to acids and bases?

An Arrhenius acid is a substance that dissociates in water to form hydrogen ions or protons (H⁺).

For example hydrochloric acid: HCl (aq) → H⁺ (aq) + Cl⁻ (aq).

An Arrhenius base is a substance that dissociates in water to form hydroxide ions (OH⁻).

For example sodium hydroxide: NaOH (aq) → Na⁺ (aq) + OH⁻ (aq).