Summer science activities for your children

Parents: Believe it or not, elementary school students only spend 2.3 hours per week in science classes. This is down 43 minutes since 1994. At the same time, educators are emphasizing that our nation’s future is linked with student success in science, technology, engineering, and mathematics.

This summer, we have selected a number of science activities that we hope will hook your children on science. They can find 40 more activities on our Dear Teacher website under “Science Activities.” All of the activities are based on scientific principles and are fun to do. Help your children choose activities that are age-appropriate and safe. The first two will be appropriate to do on the Fourth of July.

Fireworks in a glass

• Fill a tall glass almost to the top with warm water.

• Pour 1 to 2 tablespoons of oil into another glass.

• Add one drop of blue and one drop of red food coloring to the glass containing oil.

• Stir this mixture briefly to break the food coloring into smaller drops.

• Pour this mixture into the tall glass of water.

• As the food coloring sinks, it will resemble fireworks.

This experiment shows that oil is less dense than water, so it floats on top of the water. Your children will also observe that food coloring dissolves in water — but not in oil.

Fireworks in your mouth

• Go into a dark room with a mirror.

• Take the time to let your eyes adjust to the dark.

• Place a Wint-O-Green Lifesaver (not sugarless) between your teeth keeping your mouth open.

• Bite down hard on the candy, and you will see a blue-green light coming from your mouth.

The scientific name for this is “triboluminescence,” the mechanical generation of light.

Humming balloon

Find a large balloon and place a coin inside it. Then blow up the balloon and tie up the end. Move the balloon rapidly to cause the coin to roll around inside. If the coin rolls fast enough, you may hear the balloon hum. The frequency with which the coin circles the interior of the balloon is resonating with one of the balloon’s natural frequencies.

Static electricity

Static electricity is caused by an imbalance of positive or negative electrons that build up on an object that does not conduct electricity, such as a balloon. You also can observe it when you shuffle your feet across a carpet.

While you are facing a mirror, rub a balloon against the top of your hair 10 or more times. Then slowly lift the balloon upward and watch strands of your hair follow the balloon so it is standing on end. Keep moving the balloon up until your hair falls back down.

Making bubbles

You will need a glass of water and a glass of orange juice to start this experiment.

Add one teaspoon of baking soda to each glass. What will happen? You will see bubbles in the orange juice — but not in the water. This is because orange juice is an acid that frees the carbon dioxide in baking soda, and a bubbly gas is formed.

Try adding a teaspoon of baking soda to other things like yogurt, lemonade, apple juice, black coffee, and tea. You will get bubbles if it is acidic.

Magnets

Magnets are fascinating to children because of the way they both stick together and sometimes move away from each other. Playing with them in the following activities is a first step in helping children learn about magnetism. You will need inexpensive magnets of different sizes for this activity.

Magnetic attraction: Select a variety of objects that will and will not be attracted to a magnet, such as pot lids, plastic lids, paper clips, metal and wooden toys, plastic plates, coins, bolts, and a staple. Have your child use a magnet to discover which objects it will attract and then divide the objects that are and are not attracted to the magnet into separate piles. See if your child can discover what each group of objects has in common.

Making a needle compass: Supervise younger children. Your child should tap one end of a needle at least 30 times with a magnet. The other end of the needle should be covered with a piece of tape. The needle should then be stuck through the middle of a wine bottle cork. Next, label the sides of a bowl: north, south, east and west. Fill the bowl with sufficient water so that the cork with the needle will float. No matter which way the bowl is turned, the needle should always point north.

The floating egg

• Place an uncooked egg in a glass of plain water.

• Place another egg in a glass of water with 10 heaping tablespoons of salt.

• Observe what happens.

• Remove the eggs from the glasses and pour out half of the plain water. Refill the glass with the saltwater.

• Place an egg in this mixture and observe what happens.

You have learned about density. Saltwater is denser than plain water, so the egg rises to the top.

The soft egg shell

• Use a pin to make a hole on the ends of an uncooked egg.

• Blow the insides of the egg out through one of the holes. If this doesn’t work, make the hole larger.

• Put the empty eggshell in a cup filled with a sugary soda, and leave it there for 24 hours.

• Observe what has happened to the eggshell.

• Think about what soda might do to your teeth.

Parents should send questions and comments to dearteacher@dearteacher.com or ask them on the columnists’ website at www.dearteacher.com.

© Compass Syndicate Corporation, 2014.

Distributed by King Features Syndicate