Give scientific reasons.

A. Foam accumulates on at the surface of ‘dal’ kept for a long time in summer.

B. Why are naphthalene balls kept with clothes to be put away?

A. Foam gets accumulated on the surface of the dal, this happens due to denaturation of protein at high temperature in summer. Denaturation is a process in which protein molecules loses its structure due to breaking of weak chemical bonds.

B. Naphthalene balls are organic compound which have the properties of sublimation. Sublimation is a process in which a solid matter changes to gas without in between liquid phase. The gas which releases from naphthalene balls keeps insect away from the kept away clothes.