In a glass capillary tube,the shape of the surface of the liquid depends upon:

Explain why:
$(a)$ The angle of contact of mercury with glass is obtuse,while that of water with glass is acute.
$(b)$ Water on a clean glass surface tends to spread out while mercury on the same surface tends to form drops. (Put differently,water wets glass while mercury does not.)
$(c)$ Surface tension of a liquid is independent of the area of the surface.
$(d)$ Water with detergent dissolved in it should have small angles of contact.
$(e)$ $A$ drop of liquid under no external forces is always spherical in shape.

The spiders and insects move and run about on the surface of water without sinking because

Cohesive force is experienced between

$A$ drop of oil is placed on the surface of water. Which of the following statements is correct?

Explain surface tension in the context of potential energy.