4. Differentiate between a physical and a chemical change with reference to
(a) nature of change
(b) formation of products
(c) energy change
Answers
Explanation:
a.Physical change refers to a change in which the molecules are rearranged but their internal composition remains same. Chemical Change is a process in which the substance transforms into a new substance, having different chemical composition.
b.The difference between a physical reaction and a chemical reaction is composition. 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.
c.A chemical change is a permanent change. A Physical change affects only physical properties i.e. shape, size, etc. A physical change involves very little to no absorption of energy. During a chemical reaction, absorption and evolution of energy take place
Answer:
A chemical change is a permanent change. A Physical change affects only physical properties i.e. shape, size, etc. ... Some examples of physical change are freezing of water, melting of wax, boiling of water, etc. A few examples of chemical change are digestion of food, burning of coal, rusting, etc.