Science can be a fun subject for kids, especially when the learning includes exciting experiments where scientific principles lead to magical results. In this article, I’ll detail a few great experiments that are simple, fun, and teach your child all about the wonders of liquids.
1. Water Lasso:
What you’ll need:
A bowl
Water
String
Dish soap
A matchstick or dowel
Step One: Fill a bowl with water.
Step Two: Knot a piece of string so that it forms a loop, about 2″-3″ (about 2.5-5 cm) in diameter.
Step Three: Dip a matchstick or dowel into dish soap. Put the loop into the water and watch it form an irregular shape.
Step Four: Lower the tip of the matchstick (or dowel) into the middle of the loop. Like magic, the irregularly shaped piece of string will expand into a round lasso shape
Why does it work?
When the soapy matchstick or dowel is dipped into the water, the soap spreads out in every direction, breaking the surface tension of the water as the soap penetrates the water particles. When the water particles move outward, they push on the string, making it open up into a perfectly round shape.
2. Water Lilly:
What you’ll need:
Paper (a blank piece of printer paper works best)
Crayons
Scissors (if necessary, make sure there is an adult to help with the scissors)
Sink or large bowl
Water
Step One: Cut a flower shape (have an adult help, if necessary) out of a piece of paper. This experiment works best when the flower shape has a lot of long petals, almost resembling a star shape.
Step Two: Color the flower. This will make the end result even better!
Step Three: Fold the petals inward tightly, so that the flower stays closed. Fill a sink or large bowl with water.
Step Four: Put the folded up flower into the water, and watch as the petals open in slow motion to reveal a colorful flower.
Why does it work?
Since paper is made of plant material pulp, and the plant fiber capillaries allow water to travel throughout the sheet of paper, the flower (paper) swells as it gets wet. As the paper flower swells in the water, the petals unfold into the original flower shape. A similar, neat trick that always kept me entertained was breaking a toothpick in half, and dropping it into a small puddle of water. Like magic, the toothpick moves and starts to straighten!
3. Nearly Impossible Coin Game:
What you’ll need:
A large glass container (a large jar, vase, etc.)
A very small glass (a shot glass works best)
Coins
Water
Step One: Put the small glass in the center of the large container.
Step Two: Fill the large container with water, being careful not to disturb the small glass at the bottom of the container.
Step Three: Try to drop a coin into the small glass. You’ll notice that, even with very careful aim and a steady hand, the coin will glide through the water and go off to the side of the small glass. It is virtually impossible to get the coin to fall straight down into the small glass.
Why does it work?
It is nearly impossible to get the coin to fall straight down in the water, because even the tiniest slope or movement disrupts the water. In the case of a slope, the water slant causes resistance under the coin as it falls. Since the coin’s center of gravity is in its middle, the coin is easily affected, and it usually flips and slides to the side of the container.
4. Water Beads:
What you’ll need:
A faucet
Your own finger (this is a cheap experiment!)
Step One: Turn the faucet on low until you have a thin stream of water running into the sink.
Step Two: Put your finger under the stream of water. Move it slowly up towards the faucet and watch as the wavy stream turns into larger balls that resemble a string of beads made out of water.
Why does it work?
The water particles are held together by surface tension. When your finger is in the stream of water, the liquid gets so obstructed that, due to the surface tension, it becomes bead-like. As you move your finger down, the water speed increases, and the “beads” go away, turning back into a stream.
