Question

Could u say me the difference between physical and chemical changes?

Answer 1

physical change means when reaction takes place the substance is getting change into other state and it can regains its original state back after sometime when reaction takes place. it is a temporary change
eg: melting of wax 
if we light a candle the wax change into liquid state and after regain its solid state

chemical change is a permanant change. it cant regain its state after the reaction takes place
eg: burning of crackers, rusting of iron etc

Answer 2

Physical change:
A Physical change is a reversible one.(products can be brought back to reactants)
No New products are formed.
It is a fast process.
No emission of heat or light.
eg: melting of ice


Chemical change:
A chemical change is irreversible one.(products cannot be brought back to reactants)
New products are formed.
It is mainly a long process and takes much time.
Heat or light may be emitted.
eg: burning of fuels