Parents: Children learn best when instruction is continuous. Here are some science activities they will enjoy over the summer. All of the experiments are based on scientific principles that also let kids see the fun side of science. Make sure that the ones that your children do are age-appropriate and safe. As they do these experiments, they may also be practicing their reading, writing, math and thinking skills. And if they become hooked on science, there are many websites offering more experiments, including exploratorium.edu/explore/handson.html, sciencemadesimple.com/projects.html and pbskids.org/zoom/activities/sci.
Experiment No. 1: Which fruit decays the fastest? This is fun because your children will see the fruit blow up a balloon. When fruit decays, bacteria multiply as they eat up the fruit. In processing the food, the bacteria give off gas.
Mash a ripe banana and put it into a bottle. Then place a balloon over the mouth of the bottle, and put the bottle in a warm, sunny place. Measure how far the balloon inflates each day for a few days. Do the same thing with other fruit, such as grapes, apples and oranges, to answer the experiment question.
Experiment No. 2: Is one eye better than two? You’ll need an eye patch and a fairly small ball for this experiment. Two children should stand several feet apart and toss the ball back and forth 10 times. Older children should catch the ball with one hand. Then, one child should put on an eye patch. Again, the children should toss the ball to each other. Total how many times the child caught the ball with and without the eye patch. Then have the other child use the eye patch.
Experiment No. 3: Is your skin the same everywhere? Make a big black area of about 3 inches by rubbing a soft pencil on a sheet of paper. Put a finger on the spot until it picks up a big smudge. Then pick up the smudge from your finger with a piece of Scotch tape, and press it onto a piece of white paper. Do the same with other parts of your body. Did your skin prints differ?
Experiment No. 4: How hard is your heart working? Take your pulse lying down and then after doing these exercises: sitting, standing and jumping 10 times. Rest between each activity. Does your pulse rate change with what you do?
Experiment No. 5: Does air expand when it is heated? Blow up a balloon and measure the distance around it at its widest point (circumference). Next, turn on a lamp and hold the balloon above it for 2 to 3 minutes. Then measure the distance around the balloon’s circumference again. What happened to the size of the balloon?
Experiment No. 6: Ask your children if they think that it is possible to stick a pin in a balloon without popping it. Blow up a latex balloon until it is about three-quarters full of air, and tie off the end. Next, cut seven pieces of strong, sticky tape, and secure each one firmly to the outside of the balloon. Try to space them evenly. Then carefully stick a straight pin through the middle of each piece of tape. Why didn’t the balloon burst? (The sticky tape forms a seal around the pin.)
Experiment No. 7: Have your children find out if warm or cool air takes up more room? Help or supervise younger children with this experiment, as hot water is used. Have your children find a large plastic bottle, like a 1-gallon milk jug. Pour hot tap water into the bottle until it is about half-full and then swish it around in the bottle for about a minute. Pour the water out of the bottle, and immediately screw the cap on tightly. Watch the bottle collapse.
What has happened is that the air in the bottle was warmed by putting the hot water in the bottle. When the bottle was capped, this warm air quickly cooled. Cool air takes up less room than warm air. The bottle collapsed to fill the space. It was pushed in by the outside air pressure on all surfaces of the bottle.
Experiment No. 8: Gravity causes all objects to be pulled toward each other. Because Earth is the biggest object around, it has the strongest pull of gravity. How does gravity work? Place a marble in a bottle. Turn the bottle over. What happens? Again, place a marble in a bottle. Move the bottle so the marble starts going around inside it. Keep moving the bottle, and gradually turn the bottle on its side and then upside down. Did the marble fall out of the bottle? It shouldn’t have. Centrifugal force should have pulled the marble away from the bottle neck and overcome the gravity that would cause it to fall out.