Seal with Air

Stop water falling out of an upturned glass. A card can stick to a glass and keep the water in it, as if by magic! Air pressure forces the card upwards, against the glass. The pressure is strong enough to stop the weight of waterpushing the card away.

Materials:
1. Thin flat card
2. Glass
3. Water

Procedure:
1. Hold the glass over a sink or a basin. Carefully pour some water into the glass.
2. Place the card on the glass. Hold down so the eard touches the rim all the way around.
3. Still holding the card turns the glass upside-down. Let go the card. The water stays in the glass!