lab: Fluorescent Tube and Static Electricity

GRADE SCHOOL LAB
LIGHTING A FLUORESCENT LIGHT BULB
WITH STATIC ELECTRICITY

INTRODUCTION:

When an electrical current is applied to a fluorescent tube, electricity jumps from one end of the tube to the other. This produces ultraviolet light which is invisible to the human eye. Mercury vapor inside the tube carries electrons to the phosphor powder coating the inside of the tube. This coating changes the ultraviolet energy into visible light energy. When an object with a static electric charge is brought close to the fluorescent tube, electrons move to the tube causing the same effect, only on a smaller scale.

In this lab, you will expose a fluorescent bulb to a balloon you have given a negative charge to, and observe this effect.

MATERIALS NEEDED:

9 inch round balloon
Fluorescent tube
Clean, dry, oil-free hair

PROCEDURE:

CAUTION: Handle the fluorescent tube very carefully. They can break easily.

Wash the outside of the fluorescent tube and thoroughly dry.

Inflate and tie the balloon.

In a dark room hold the tube at one end, with the other end resting on the floor.

Rub the balloon against your hair 10 to 15 times. The balloon picks up electrons from your hair and will become negatively charged.

Hold the balloon very close to the tube, and slowly move it up and down along the side of the tube.

What do you observe happening?

VARIATION:

Try rubbing the balloon rapidly up and down on the tube, instead of your hair. This removes electrons from the tube to the balloon, giving the balloon a negative charge, and the tube a positive charge. Hold the balloon very close to the tube as before and observe what happens.

Try using a plastic comb instead of the balloon.

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