Water is especially cohesive because of its polarity and hydrogen bonding. Cohesion is the attraction between molecules of a substance. The cohesiveness of water causes it to have a high surface tension. Surface tension results from molecules on the surface of a liquid being attracted only to molecules on the sides or underneath, whereas the molecules not on the surface are attracted to molecules on all sides. This difference in attractive forces causes a liquid to assume a shape with minimum surface area – a sphere. In other words, water drops are spherically shaped because of surface tension.