In the case of the surface of one fluid in contact with another fluid or a solid surface,what does the surface tension/surface energy depend on? Explain with an illustration.

(N/A) The surface tension or surface energy at the interface between two materials depends on the nature of the materials on both sides of the interface.
$(i)$ If the molecules of the two materials attract each other,the potential energy of the interface is reduced,leading to lower surface energy.
$(ii)$ If the molecules of the two materials repel each other,the potential energy of the interface is increased,leading to higher surface energy.
Therefore,surface energy is essentially the energy of the interface between two materials and is a property that depends on the interaction between both substances.