|
Egg Into Bottle
Peel a soft-boiled egg and place it on the mouth of the bottle. Leave it
there for a while and it will get sucked inside. The vapor from the hot water drives the air out of the bottle. Once the egg
seals the top of the bottle, the air can’t get back in. As the water vapor
cools, it turns back into water, causing the pressure inside the bottle to drop.
The higher pressure of the outside air pushes the egg into the bottle. Comments
Average Rating : %
|
||||||
A Candle That Sucks Water
How Does It Work? When the candle is burning inside the glass, the heat makes the air expand, so some of the air escapes outside the glass. The candle goes out after it uses up all the oxygen, so the air inside the glass cools. As it cools, the pressure inside the glass drops. Some of the carbon dioxide formed by the flame dissolves in the water as well, decreasing the pressure even more. The water outside the glass on the saucer is forced into the glass by the higher aire pressure outside. Comments
Average Rating : %
|
||||||
A Can That Can “Walk”
When you put the balloon near the can, the can will start rolling toward the balloon. How Does It Work? When you rub the balloon with a tissue, the balloon gets a negative electric charge of several thousand volts. When you put the balloon near the can, electrostatic induction affects the molecules in the metal. The outside of the can gets a positive charge, so it is drawn toward the balloon and starts rolling in that direction. Comments
Average Rating : %
|
||||||
Keeping Water Separate
Cover the glass containing the colored water with a sheet of paper, turn it upside down and place it on top of the glass containing salt water. (Be sure to do this trick over a saucer or bowl.) Gently pull the paper out from between the glasses. The colored water and the salt water will remain separate. How Does It Work? Salt water is heavier than colored water, so the two stay separate as long as
the boundary between them isn’t disturbed. Try turning the two glasses over,
though. The heavier salt water will now be on top, so it will flow down and mix
with the colored water. Comments
Average Rating : %
|
||||||
Floating Arm
Comments
Average Rating : %
|
||||||
Soap Rainbows
Comments
Average Rating : %
|
||||||
Bubbles with Your Hands
Comments
Average Rating : %
|
||||||
Toothpick Torpedo
Drop the toothpick in a pan of water. The toothpick will start moving in the
direction of the sharp end. Shampoo contains agents that reduce the surface tension of liquids. As the
shampoo on the end of the toothpick dissolves, it reduces the water’s surface
tension around it, thus releasing the water’s hold on that end of the toothpick.
The water around the other end of the toothpick still has surface tension, so it
pulls the toothpick in that direction. Comments
Average Rating : %
|
||||||
Reading Through an Envelope
Get a piece of dark construction paper or tear out a page from a magazine
that is printed on both sides. Roll up the paper into a four-inch-long tube.
When you hold the tube against the envelope, you’ll be able to read the writing
inside. Usually you can’t read the writing inside an envelope because of the light
reflected off the envelope’s white surface. But the tube blocks that reflected
light, so you see only the light coming through the envelope. Comments
Average Rating : %
|