Experiments

 

1. Brush, Brush!

This experiment will really get kids into brushing their teeth once they scientifically prove all the good things that toothpaste can do.

1. Write on sticky notes: Soda 1, Soda 2, Juice 1, and Juice 2. Place them in a row on a counter.
2. Fill two glasses halfway with brown soda and place behind the Soda 1 and Soda 2 sticky notes. Fill two glasses halfway with lemon juice and place behind the Juice 1 and Juice 2 sticky notes.
3. Carefully place one egg in the bowl. Squeeze a big dollop — about one tablespoon — of toothpaste on top of the egg and gently rub the toothpaste all around with your hands until the egg is completely covered in a thick layer of toothpaste. Repeat with a second egg.
4. Gently submerge the toothpaste-covered eggs into the liquids: one egg in the glass labeled Soda 1 and the other egg in the glass labeled Juice 1. Wash and dry your hands.
5. Gently submerge the remaining eggs, without toothpaste on them, in the remaining glasses: one in the glass labeled Soda 2 and the other in the glass of juice labeled Juice 2. Wash and dry your hands. Leave the eggs in the glasses for 12 hours.
6. After 12 hours, remove the eggs from the glasses of soda one at a time. Rinse them in cool water and pat them dry with the towel. Place each egg by the sticky note of the glass it was in. Are the eggs the same or different colors?
7. Remove the eggs from the glasses of juice one at a time. Rinse them under the faucet and pat them dry. Place each egg by the sticky note of the glass it was in. Feel the eggs gently. Does one feel stronger or weaker than the other?
8. Write down your observations in your science notebook.

The eggshells in this experiment represent the enamel (outer coating) on your teeth. Toothpaste cleans your teeth and prevents stains: it removes food and drink particles that are stuck on your teeth. Teeth can be stained easily by dark-colored liquids like cola, coffee or tea. The egg without toothpaste will be brown and discolored. The egg covered in toothpaste was protected from turning brown.

Toothpaste also protects your pearly whites from decay (breaking down). The egg without toothpaste left in the lemon juice was worn down and soft to the touch, while the egg that was protected with toothpaste is stronger. The lemon juice is acidic, and those acids broke down the shell just as acidic drinks can wear away your tooth enamel. When a tooth is worn down, a cavity can form more easily. But the fluoride in toothpaste mixes with your saliva to create a protective coating around your tooth enamel. It helps keep your teeth strong and cavity-free.

*From Good Housekeeping Amazing Science: 83 Hands-on S.T.E.A.M Experiments for Curious Kids!

2. Grow an Avocado Tree

For an easy lesson in Earth Science, your family can grow an avocado tree from a pit. You can buy an AvoSeedo kit, or just peel the seed and suspend it over water with toothpicks.

3. Floating Fish

Here's one that deals with solubility and density.

1. Draw the outline of a fish on the bottom of a glass plate or tray in dry-erase marker. Retrace your drawing to make sure all the lines are connected. Let dry for a minute or two.
2. Fill the measuring cup with tap water. Place the pour spout just inside the corner of the dish and add water very slowly until it just covers the bottom. Be careful not to pour water directly onto your drawing or make splashes near it. The water will move toward your drawing, eventually surrounding it. Observe what happens. If the water splashes or it doesn’t work on your first try, empty the dish, erase the drawing with a paper towel, dry off the dish, and try again.
3. Tilt the dish slightly from side to side. What happens? Jot it down.

The ink in dry erase markers is engineered to be slippery. It’s made with a chemical that causes it to easily release from surfaces. (Permanent markers are made with a chemical that makes the ink stick to surfaces, so be sure not to use these in your experiment!)

The easy-release ink lets go from a surface, but why does it float? There are two reasons. First, dry erase ink isn’t soluble, which means it won’t dissolve in water. Second, dry erase ink is less dense than the water, so it becomes buoyant, meaning it can float. When you tilt the dish, the fish moves around on the water’s surface.

*From Good Housekeeping Amazing Science: 83 Hands-on S.T.E.A.M Experiments for Curious Kids!