Answer: Option (b) is the correct answer.
Explanation:
A change that does not lead to any difference in chemical composition of a substance is known as a physical change.
For example, shape, size, mass, volume, density, boiling point, etc of a substance are all physical properties.
As ice melts to form water shows that only the state of matter is changing. Hence, it is a physical change. Similarly, sugar cubes dissolve in hot coffee is also a physical change as no new compound has formed.
On the other hand, changes that lead to bring change in chemical composition of a substance is known as a chemical change.
For example, exploding dynamite, rotting cheese etc are all chemical changes.
Thus, we can conclude that both are physical changes because there is a change in the physical states of ice and sugar.
