**3. Condition to form foam**

To create a foam three condition are required.1st Condition is the mechanical work so that the surface area is increased. This can be done by, dispersing a high volume of gas in the liquid, agitation, or inserting a gas in the liquid [9, 10].

The second condition is surfactants that must be available so that surface tension decreases. And the last is foam must be produced more rapidly than it break.
