Question

the top surface of the liquid behave like stretched membrane because​

Answer 1

Explanation: This property is due to a net inward imbalanced force due to the fact that no liquid molecules are above the liquid surface molecules. Also due to this the liquid behaves as it is a stretched membrane and there are many practical evidences that prove it is stretched membrane.

Answer 2

Surface tension is the special property of a liquid due to which the liquid tends to minimize its surface area. This property is due to a net inward imbalanced force due to the fact that no liquid molecules are above the liquid surface molecules.