Question

Burning of wood and rusting of iron bar are examples of ___________ changes.

• A. physical and chemical
• B. biological
• C. physical
• D. chemical

Answer 1

The correct option is D chemical

A chemical change is any change that results in the formation of a new substance with different chemical properties.

When we burn wood, ash is formed (new substance). Rusting of iron results in the formation of a brown flaky layer (iron oxide) on the surface. The properties of these substances change after the reaction. Therefore, the burning of wood and rusting of an iron bar are examples of chemical changes.