Question

why do you say that chemical changes are irreversible and physical changes are are reversible​

Answer 1

Answer:

Chemical changes are irreversible because it is formed with new properties

Answer 2

Answer:

Physical changes occur when objects or substances undergo a change that does not change their chemical composition.  In general a physical change is reversible using physical means. For example, salt dissolved in water can be recovered by allowing the water to evaporate.While with a chemical change, a substance transforms into a different substance. Most chemical changes are irreversible. For example, you cannot unbake a cake or unburn wood. However, there are some chemical changes that are reversible, such as nitrogen dioxide that is chemically changed by heat and then reforms when cooled.

Explanation: