Physical and Chemical Changes.
In a physical change appearance or form changes, but substance remains same.
Ice on melting converts to water. Water on evaporation converts to water vapor. All the products formed are still forms of water. Hence, this is a physical change.
When wood burns, chemical reaction takes place. New substance gets formed. This is a chemical change.
When we light a matchstick, combustion reaction takes place. This is a chemical change.