Explanation:

Chemical Reaction: A chemical reaction is the change that brings about new products.

Chemical Change:

• Chemical changes produce new substances.
• Most chemical changes are irreversible.
• Chemical changes are product-oriented.
• Chemical changes follow the law of conservation of mass.

Physical Change:

• Physical changes are reversible.
• No new substance is formed in a physical change.
• Physical changes involve changes in the state of matter.

 Important Points

• Melting of ice results in water, which can be frozen back to ice, thus it is a physical change.
• Crystallization is a process that changes liquids into solids, which is again a physical change.
• Souring of milk is a chemical change because a new substance, yogurt, is formed.
• Dissolving sugar in water is the formation of a solution that can be called a mixture.
• There is no reaction in the mixture of sugar and water, so it is a physical change.

 Additional Information

Temperature: It is the degree of amount of heat and cold measured.

Boiling Point: The minimum temperature at which a liquid starts to boil is called its boiling point.

Freezing Point: The minimum temperature at which a liquid starts to freeze is called the freezing point.

Melting Point: The minimum temperature at which a solid starts to melt or changes into a liquid is called the melting point.