Question

Which of the following is a physical change?; 1) Boiling of Water; 2) Rusting of Iron; 3) Boiling of an Egg; 4) Burning of Candle

Answer 1

1) Boiling of water to form steam is a physical change because during this change only changer of  state occurs from liquid water to steam (gaseous) without any change in its chemical composition

2) Rusting of iron is a chemical change since during rusting, a new chemical compound called  hydrated iron oxide (rust) is formed.

3)boiling of egg is an chemical change as the composition of egg changes. New substance is formed and the change is irreversible.

4)Burning of candle is both physical and chemical change:- When the candle burns, the wax slowly melts which freezes after some time (Physical change). Burning of wick (the thread of the candle) is a chemical change as it involves combustion.

hope this helps

Answer 2

1. Cutting of trees: Physical change.

2. Melting of butter in a pan: Physical change.

3. Rusting of almirah: chemical change.

4. Boiling of water to form steam: physical change.