Kids are born researchers. (Yours have probably asked “why” 14 times already today!) Entertain them and illustrate basic scientific concepts with five easy experiments — no Ph.D. required.
According to koodakpress،
The Method Draw a wavy line an inch from the bottom of each towel strip, using a different color pen on each. (Older kids should note which color is on which strip.) Dip each strip into the water so that the bottom edge of the paper towel is submerged, but not the line of ink; hold in place as the water creeps up the towel. The ink marks will spread, revealing the different dyes that make up each color.
Most colors are actually made up of several different dyes. As the paper towel draws the liquid out of the bowl, the water molecules bond with the different ink molecules and spread them. The process of separating these dyes (or the components of any mixture) is known as chromatography. You’ll likely find that purple leaves a line of blue and a smear of red, and that green breaks up into blue and yellow. As for the black marker, don’t be surprised if it’s made of different blues — and even red. To take the exploration further, have your kid cover her eyes while you draw a line on a fresh strip. Dip it into the water; once the ink has spread, have her open her eyes and try to guess which marker you used.
The Method Glue the bottom of the sport-top over the hole in the CD; let dry. Seal the bottle top’s base with duct tape, covering the glued area so air can’t escape. Stretch the balloon over the spout. With the sport-top open, inflate the balloon by blowing into it through the hole in the CD. Then click the top shut so the balloon stays inflated. Set your creation on a table and gently pull the sport-top open. The air coming out of the balloon will lift your craft; give it a push to send it zipping across the room. Next try pushing the hovercraft while it’s deflated. Notice that it moves more slowly.
The inflated balloon wants to shrink back to its natural shape; since it isn’t sealed, it pushes air out of the hole in the CD. The force of air escaping lifts the CD, so it hovers above the table, says David Epley, aka Doktor Kaboom!, star and creator of the science DVD Try This at Home. It’s a simple lesson about friction. Why does the craft move faster when the balloon is inflated? “Putting the air between the CD and the table keeps them from rubbing against each other, which slows things down.”
The Method Glue the base of the plastic cup to one end of the ruler. Once it’s dry, create a mini teeter-totter by leaning the center of the ruler against the rock, so the cup faces up. Put a ball in the cup and, with your child standing off to the side of the tiny seesaw, have him press on the other end of the ruler. “This will cause the other end to flip up, and the ball to fly out,” says Sean Connolly, author of The Book of Potentially Catastrophic Science. If you press harder, the ball should fly out faster.