Science Experiments

Here are some ideas for science fair projects and experiments.

Watch a plant drink water
Put 6 to 10 drops of food coloring into a plastic cup one quarter filled with water. Cut about 1/2 inch off the bottom end of a celery stem that has leaves. Put the cut end into the colored water. You should see results in between 4 and 24 hours. Color will slowly travel up into the plant. Any white flower such as a carnation or Queen Anne's lace [wild carrot] works very well. You could use three flowers, each in differently colored water. Or a single stem can be split into halves and each half put into its own container with the two containers having differently colored water. Red, blue and yellow coloring shows up best. Use enough to make the water bright. Ink can also be used. Short stems produce results faster. If a celery stalk without leaves is used also cut about 1/2 inch off the top.

Weight of water
Find two bottles whose mouths are the same size. Put hot water into one bottle. Mix water soluble paint, ink or food coloring with the hot water to make it more visible. Put cold water in the other bottle. Both bottles should be completely full. Put a thin card or piece of thin stiff plastic across the top of the bottle of cold water. Hold the card in place while you invert the bottle and place it on top of the other bottle. Carefully pull out the card. The denser cold water slowly sinks while the hot water rises to float on top of the cold water. As the colored water rises it forms interesting shapes something like rising smoke.

Peel and egg with vinegar
Place an uncooked egg in a small glass. Cover the egg with vinegar. Wait two days and check the firmness of the shell. You will find the shell to be almost as soft as a balloon. The hard part of the shell is the chemical calcium carbonate. Vinegar and calcium carbonate combine chemically. As the chemical reaction takes place the shell gradually dissolves into the solution.

Boil water with ice
Under certain conditions ice can be used to boil water. Use a thick glass jar with a metal lid of the type with a plastic seal. A 4 to 12 ounce jelly or baby food jar should work well. Fill the jar half full with water and boil the water for one minute in a microwave oven with the lid off the jar. Open the; oven and place the lid on the jar very loosely. Wear safety glasses as a precaution. Boil the water for another 30 seconds. Immediately screw the lid down tight using a towel to protect your hands. Remove the jar from the microwave. Wait until you are sure the water has stopped boiling, then place an ice cube on top of the metal lid. A dishcloth wrapped around the ice cube but not under it, will soak up the water from melting ice. Within a few seconds you will see the water boil again. You may be able to keep it boiling for 5 minutes by replacing ice cubes after they melt away and wringing out the dishcloth. This works because steam displaced the air above the water when the jar was in the microwave oven. The ice condenses the water vapor into liquid leaving very little of anything in the space above the water. The very low pressure that results lets the water boil even though its temperature is much below its normal boiling point. After the water has cooled enough it will no longer boil by applying ice. If the lid is left tightly sealed it can be made to work again by placing the jar for about 2 minutes in a pan of very hot water. Do not heat the sealed jar in a microwave oven or directly on a stove, all the ingredients for a glass shrapnel bomb are there.