BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Since the size of a pencil reduces once broken, it can be said as an example of physical change.

Detailed explanation-2: -Breaking of pencil is a physical change.

Detailed explanation-3: -Melting of ice is not an example of chemical change as the chemical composition of water remains the same even after melting.

Detailed explanation-4: -Breaking is a physical change because the shards are still glass, but it can’t be easily made whole again.

Detailed explanation-5: -Note: Breaking a brick, evaporation of liquid, and moving a wheel, are examples of physical changes as no change is observed in the chemical composition in carrying out these processes.