Water and Oil Drop

Liquids, such as water or oil, can form droplets that are held together by **surface tension**. Surface tension is a result of a **cohesive force** and it causes the surface of many liquids to behave as an elastic membrane.



Because liquid droplets are fairly simple to study and control under different conditions, they have fascinated experimentalists for more than two centuries.



Molecules at the liquid surface puddle **attract more to one other than they do to the air molecules above them**. This causes specific features of the surface and also it effects on formation of a droplet shape. Surface tension prevents the molecules from falling out and spilling. The sizes of drops coming out of the dropper are different for different types of liquid. Oil drops are smaller than water drops; even they are falling down from the same dropper. That is because the **molecules in each liquid are attracted to one another to a different degree**. So the surface tension of each liquid is different.