In this experiment, you will be able to sink and raise an eye-dropper by changing its density.
Things Required:
Soda bottle
Glass eyedropper
5-inch balloon
Directions:
Fill the soda bottle so that it may overflow with water. Partially fill the eye-dropper with water and place it in the bottle. The eyedropper should float; if it sinks, squeeze some of the water out of the bulb. Add water to the bottle until it overflows. Attach the balloon to the mouth of the bottle.
Push down on the balloon, and then release.
This Is What Happens:
The eye-dropper sinks and rises.
Science Behind It:
Pushing down on the balloon causes water to move into the eye-dropper. This extra water makes the dropper heavier and it sinks. Releasing the balloon decreases the pressure in the bottle and the excess water moves out of the dropper. Being lighter, it now rises. The eye-dropper changes only its weight by the addition and loss of the water. Since its size remains constant, one can say that the density of the dropper changed. Density is a measure of weight for a specific size.
