Published: Friday 10 March 2006 - Updated: Tuesday 29 March 2011
To demonstrate capillarity in water and mercury.
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For water the attractive force between a glass and a water molecule (adhesion) is greater than that between two water molecules (cohesion). The result is that the water rises to a height depending on the tube diameter. For mercury the level in the capillary tube is depressed since in this case the forces of cohesion exceed those of adhesion.