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Liquids tend to form spherical droplets because of surface tension. There is energy associated with the surface tension, and since a sphere has the minimum surface to volume ratio, it has the minimum surface tension related energy for a given amount of liquid. (It is a general principle in physics that things tend toward a minimum energy state.)
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Surface tension is a property of the surface of a liquid. It is what causes the surface portion of liquid to be attracted to another surface, such as that of another portion of liquid (as in connecting bits of water or as in a drop of Mercury that forms a cohesive ball).
Surface tension is caused by cohesion (the attraction of molecules to like molecules). Since the molecules on the surface of the liquid are not surrounded by like molecules on all sides, they are more attracted to their neighbors on the surface.
Applying Newtonian physics to the forces that arise due to surface tension accurately predicts many liquid behaviors that are so commonplace that most people take them for granted. Applying thermodynamics to those same forces further predicts other more subtle liquid behaviors.
Surface tension has the dimension of force per unit length, or of energy per unit area. The two are equivalent - but when referring to energy per unit of area, people use the term surface energy - which is a more general term in the sense that it applies also to solids and not just liquids.
In materials science, surface tension is used for either surface stress or surface free energy.
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The pull on the surface of the liquids that allow liquids to form drops when they fall?
It is surface tension.
Why water drops that fall on a surface tend to form rounded drops or beads?
The inherent property of any substance is to aggregate together, which is caused by Van der Waals' forces. These forces cause the molecules to be held together and create surface tension, in the case of liquids. When you drop water onto a surface, the water molecules adhere together due to holding those forces and try to come closer. Geometrically, a sphere has the greatest surface area to volume ratio, which is also the most stable shape for liquids to conform into. Thus, you get rounded drops or beads.
Why are raindrops shaped like tear drops?
When first formed, raindrops are nearly perfect spheres which may be several inches in diameter. As they fall, air resistance causes them to flatten out and break into many small parts. Very small drops may remain spherical, but most will be irregular shapes. See the related link for photographs.
Why falling drop of liquid is spherical?
Yes it is. Surface tension caused by hydrogen bonding within the water is the reason. Hydrogen bonding is caused by the strong polar nature of the water molecule. It's polarity means the positive end of one molecule is attracted to the negative end of another molecule.
What force of attraction is responsible for the formation of a thin film on the surface of water?
The attraction that causes water and other liquids to form drops and thin films is cohesion. The attraction between oppositely charges ions results in the formation of an ionic bond.
