Question

Classify the following changes into physical and chemical changes.

• Melting of wax.
• Magnetisation of iron
• Digestion of food
• Burning of a candle
• Sublimation of iodine
• Rusting of iron
• Stretching a rubber band
• Burning of a piece of magnesium ribbon

Answer 1

Classification of the following changes into physical and chemical changes:

Physical change: The change in which no new substance is formed and the chemical composition of the original substance is not altered.	Chemical change: A permanent change in which the original substance loses its composition and properties and gives rise to one or more new substances with different compositions and properties.
Melting of wax	Digestion of food
Magnetisation of iron	Rusting of iron
Sublimation of iodine	Burning of a piece of magnesium ribbon
Stretching a rubber band	Burning of a candle