EXPLORATORIUM INSTITUTE FOR INQUIRY

Foam Activity

Guided Activity Worksheet

Foam is a material made up of gas bubbles separated from one another by a liquid film. Foam has physical properties which can serve as a model for may other phenomena. It also serves as a vehicle for learning about the complexities of surface area. In the following investigation, you will explore some of the physical properties of foam.

Materials
(for each group)

• two 6" desert size plastic coated plates
• 2 bowls
• 1 teaspoon
• 1 cup (about 8 oz.)
• 1 or preferably 2 hand mixers
• one set of pointed dowels
• 1 ruler
• 1 magnifying glass
• optional: spoons or tongue depressors

Directions
Put 1 tsp. of Joy or Dawn detergent and 1 cup (8 oz.) of water in each of two bowls.
Beat each mixture with an eggbeater counting the strokes.
    Bowl A   200 strokes
    Bowl B   600 strokes

1/ Which foam has bigger bubbles, A or B?

On the small plastic plates, build piles of foam as high as you can.
2/ How high a pile can you build with A? How high a pile can you build with B?

On small plastic plates, build mounds of foam 4 inches high; one with foam A and one with foam B. Try to make a dowel stand vertically in the foam, with the pointed end of the dowel down.

3/ Which is the longest dowel that will stand in foam A? Which is the longest dowel that will stand in foam B?

4/ Which foam is the strongest, A or B?

5/ In the experiments above, what other differences did you notice between foam A and B?