Question

What is surf extension?

Answer 1

Dear student,
Hope you have asked for the explanation of surface tension. Here is the answer.
surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible.
consider a beaker full of a liquid, say water. Consider a molecule at the middle of the water. It is surrounded by same kind of atoms/molecules. All molecules will exert almost same force of attraction on this molecule from all direction, causing net force to be zero on the molecule. Now if you consider a molecule or atom at the surface, it is having different kinds of molecules in both sides, and hence will have different forces of attraction. This will result in a tension on the surface( actually on all the molecules of surface) of the fluid. This is what we call surface tension. Due to there isian unbalanced force on it, a fuild molecule will require a higher energy tonmake it stable. To reduce this energy requirements, fuilds will take a shape of minimum surface area. This is why water droplets are spherical, as sphere has the minimum surface area for a given volume. Surface tension allows insects (e.g. water striders), usually denser than water, to float and stride on a water surface. You will learn more about it in your higher classes.
thank you.