PRESENTED BY: Cindy Larson-Miller

BORROWED FROM: Saturday Science Activities

SUBJECT AREAS: Physical Science, Health

CONCEPTS COVERED: Air pressure, food content

MATERIALS:

A clean, empty plastic syringe

Several marshmallows

PROCEDURE:

1. Place the marshmallows in the barrel of the syringe.

2. Cover the tip of the syringe with your finger during the demo.

3. Pull the syringe back and watch what happens to the marshmallow.

4. Plunge the syringe forward and watch what happens to the marshmallow.

QUESTIONS:

1. Ask the students to predict what will happen to the marshmallow.

2. Is there a change in the size of the marshmallow? Why?

3. What does this mean about the content of the marshmallow?

4. What is being compressed, the air or the marshmallow?

RATIONALE:

As you pull back the plunger on the syringe, you are decreasing the air pressure in the barrel of the syringe by allowing the air molecules more space to move around in. The air in the marshmallow "pushes" out and causes it to expand. The opposite happens when you push in on the plunger. As the air pressure increases the marshmallow is compressed.

APPLICATION: To be added by user