Explanation:Chemical reaction: The chemical reaction is said to be the change that brings new products.Chemical change:Chemical changes give rise to the formation of new substances.Most of the chemical changes are non- reversible.Chemical changes are product-oriented.Chemical changes follow the law of conservation of mass.Physical change:Physical changes are reversible.There are no new substances formed in a physical change.Physical changes involve changes in the state of matter.Important PointsMelting of ice gives water which can be easily reversed by freezing the water again thus it is a physical change.Crystallization is a process to change liquids and make them solids which is again a physical change.Turning the milk sour is a chemical change as the new substance is formed that is curd.Dissolving sugar in water is the preparation of a solution that can be said as a mixture.In the mixture of sugar and water, no reaction takes place thus it is a physical change.Additional InformationTemperature: The degree to measure the amount of hotness and coldness.Boiling Point: The minimum temperature at which a liquid starts boiling is called its boiling point.Freezing Point: The minimum temperature at which liquid starts getting frozen or solidified is called its freezing point.Melting Point: The minimum temperature at which a solid starts melting or converts into liquid is called the melting point.