Topic: Surface Tension. Why are drops spherical? Because personally, I am fond of spherical shapes as compared to squares. No. It is because of surface tension. Surface tension is the property of liquids by which surface molecules of a liquid. Try to hold the liquid together by acquiring minimum surface area and acting like a stretched membrane. You know what, everything just went over my head. Alright. I will explain. Inside a drop, each water molecule is pulled with a force by its neighboring molecules. As these forces are equal and opposite, they get neutralized. However, the molecule present at the surface is not attracted outwards. It is attracted only inwards and sideways. Sideways forces get neutralized. But because of the inward force. Each surface molecule contracts to form a shape that has minimum surface area which is a sphere.