Question

explain why burning of wood and cutting of food into small pieces and considered as two different types of things

Answer 1

Burning of wood is a chemical change because in burning new substances are formed as

Wood + Oxygen —> Charcoal + Carbon dioxide + Heat + Light 

But cutting it into small pieces is physical change because no new substance is formed. We can only reduce the size of wood.

Answer 2

burning of wood is a chemical change as new substance is formed and by cutting food into pieces no new substance is firmed the originsl substance remains in its original form so it is a physical change