Question

when a candle burns, both physical and chemical changes take place.Identify these changes.

Answer 1

When a candle burns, both physical & chemical changes occur.
Physical Changes in Burning Candle: On heating, candle wax melts and form liquid wax. It  is a physical change. Since it again turns into solid wax on cooling. This is a reversible change.
Chemical Changes in Burning Candle: When you light the candle, the wax present near the wick will melt. Wick absorbs the liquid wax. The liquid wax vaporizes due the heat produced by the flame. This wax vapor near to flame burns and gives new substances like Carbon Dioxide, Carbon soot, water vapours, heat and light. This is an irreversible change.

Answer 2

Answer:

In a burning candle, there are both physical and chemical changes. The melting of the solid wax to form liquid wax and the evaporation of liquid wax to form wax vapour are physical changes. The burning of the wax vapour is a chemical change.