We picked out eight astounding experiments which children find simply breathtaking. We’re convinced that even when they find out what’s going on, they won’t be any less amazed.
8. An egg in a bottle
You need: An egg, a bottle with a neck which is smaller in diameter than the egg, a thin strip of paper and a drop of vegetable oil.
Experiment: Is it possible to squeeze an ordinary egg into a bottle without breaking it? It is! First, boil the egg and remove the shell. Smear some vegetable oil on the neck of the bottle. Set the thin strip of paper alight and place it on the bottom of the bottle, then place the egg on the neck of the bottle straight away. The egg will be sucked inside.
What’s happening here? The flame burns the oxygen in the bottle, leading to the formation of rarefied air inside. The reduced pressure inside the bottle together with the normal pressure outside both act to squeeze the egg into the bottle. Thanks to its flexibility, the egg fits through the narrow neck of the bottle.
7. A cola fountain
You need: A two-liter bottle of Diet Coca-Cola and five to six Mentos sweets.
Experiment: It’s best to do this one outside if you don’t want to have Coca-Cola splashed all over your house. Drop the Mentos into the Coke — the reaction is almost instantaneous. To make it easier, you can put them on a bent piece of paper and allow them to slide into the liquid. Remember to get out of the way as fast as you can once you’ve dropped the Mentos in.
What’s happening here? The sweets free up the carbon dioxide gas in the Coke, causing it to turn to foam very quickly and rise up out of the bottle like a fountain.
6. A skewer through a balloon
You need: a balloon, wooden skewers, and a small amount of baby shampoo or vegetable oil.
Experiment: Blow up the balloon to a medium size. Soak the skewer in oil and push it gently but firmly through the balloon. Keep spinning and pushing the skewer slowly until it breaks through the other side. Your kids will be utterly surprised to see that the balloon doesn’t burst.
What’s happening here: A rubber balloon is made up of a long chain of molecules called polymers, which get stretched when the balloon is inflated. As you pierce the balloon with a wooden skewer, the polymer chains are pushed aside, but remain connected, hence the balloon doesn’t burst. Soaking the tip of the skewer in oil also helps to prevent the balloon from popping.
5. A burning match
You need: Some matches, a torch.
Experiment: Light a match and hold it about 10-15 centimeters away from the wall. Shine a torch over your hand holding the match. You’ll notice that only the shadow of your hand and the matchstick itself will appear on the wall — the flame will not appear.
What’s happening here?: Fire does not produce a shadow, because it doesn’t impede the passage of light through itself in the same way that physical materials do.
4. Ice gems painted from the inside
You need: Ice cube trays (cups or bowls also work), a tray with sides, salt, food coloring or paint; some pipettes or teaspoons.
Experiment: In the evening, prepare some ice cubes in ice cube trays or several cups and bowls. The next day, prepare some strong salt solutions in several containers, and add some paint or food coloring to them. Place the ice cubes on the tray, and using a pipette or a teaspoon, place a few droplets of the salt solution on them. The salt will dissolve the ice, drilling little holes in it, and the paint will create beautiful patterns inside the cubes.
What’s happening here? When sodium comes into contact with ice, the reaction causes heat to be released, melting the ice
3. Rain at home
You need: A large transparent container (a jar, a salad bowl), water, a pipette or a teaspoon, liquid food coloring, some washing up liquid.
Experiment: Pour some water into the container and use washing up liquid to make large foam ’clouds’ on the surface. Then use the pipette or teaspoon to leave a few drops of food coloring in various places on the surface of the foam. Wait a moment, then you should see ’rain’ emerging from the bottom.
What’s happening here? Because it more dense, the food coloring trickles through the foam and sinks to the bottom of the water. This experiment is a great way to explain to kids how rain works in real life.
2. Dancing worms made from starch
You need: Cornstarch, water, a thin metal baking tray, a subwoofer from a stereo, food coloring.
Experiment: Mix two cups of cornstarch together with one cup of water. Pour the mixture onto the tray, add a few drops of food coloring and then place the tray on the subwoofer. Turn on some music, carefully pressing the tray against it with your fingers, and watch the little worms dance!
What’s happening here? Water mixed with cornstarch is a Non-Newtonian Fluid, which behaves in a completely different way to what we expect. If force is applied to it (hit it, press it, squeeze it, etc.), it becomes hard. The music acts like physical blows against it. The mixture moves and gets thicker in response.
1. Fake nail
You need: Two nails, a piece of gauze, red paint.
Experiment: This is not really an experiment but an illusion to entertain your friends. Take a nail, and cut it in half beforehand. Attach the two halves of the nail to the gauze, and wrap it around your finger to make it look like the nail has pierced through it. Red paint will help create an authentic effect. Now, to impress your friends, take a whole nail and a hammer, and put your other hand on a table under a cloth with the contraption hidden in your palm. While hitting the whole nail with the hammer, put one of your fingers through the gauze. When you take away the cover, your friends will see the nail struck through your finger.