Question

Why rusting of iron cannot be called a periodic change?

Answer 1

Periodic change: The type of change that repeats at regular intervals of time is called periodic change.

• The formation of rust is a new substance formed by the reaction of oxygen with iron which is termed a chemical change and cannot be reversed.
• Chemical change: A change in which the composition and chemical properties of the substance get changed is called a chemical change.
  Example: Digestion of food, Rusting of iron, etc.
• Hence, rusting of iron is not a periodic change.