How does a sponge absorb water? I am studying for YIPT questions. I want to know what are the parameters that help sponge to absorb liquid ?
 A: Sponges absorb liquids by capillary action. This link mentioned is to Wikipedia and basically explains what these parameters are.
As mentioned in this link:
Capillary action (sometimes capillarity, capillary motion, capillary effect, or wicking) is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a biological cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid.
We see terms mentioned here like intermolecular forces, surface tension, cohesion and adhesion which are all relevant to how sponges work.
For more information, see the Wikipedia article for sponges.
