When base reacts with water they form hydroxide ion.
For example, NH₃ + H₂O ----------> NH₄⁺ + OH⁻
(Ammonia) (Water) (Ammonium) (Hydroxide ion).
In case of strong and week base, generally weak bases partially reacts with water to produce hydroxide ions. Whereas strong base completely reacts with water to produce hydroxide ions And the reaction between a strong acid and a strong base produces salt and water and reaction is called neutralization reaction as both acid and base get neutralized.
Result: On reaction of base with water gives hydroxide ion.
Explanation: Alkali Earths or Group II has an ionization charge of a + 2. Alkali Metals have a ionization a + 1. Halogens or cold elements have a ionization of a +3.
