Question

b) (i) Distinguish between physical and chemical changes.
(ii) How can we identify a physical change as either reversible or irreversible?
Use examples to support your answer.

Answer 1

Answer:

(i) In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.

(ii) Physical changes are changes that occur in the physical properties of the substance, like shape, size, and nature. Physical changes may or may not be reversible changes. Like, turning of water into ice is an example of reversible changes but growth in height is an irreversible change.