Step-by-step explanation:
According to Arrhenius concept:
An acid is defined as a substance which donates hydronium ions 
 in water.
 in water.

For example: hydrochloric acid , nitric acid etc.


A base is defined as a substance which donates hydroxide ions 
 when dissolved in water.
 when dissolved in water.

For example: sodium hydroxide, calcium hydroxide etc.

