Inflate a balloon in a bottle!
At first, a glass bottle and a balloon are required.
Hot water or hot tea is poured into a bottle as shown in a photo.
Just after the pouring, you should cover the entrance of the bottle with the balloon, immediately.
Wait for a hour or so.
Air in the bottle is cooled and you'll find that the bottle is negative pressure.
Look at the bottle as shown in here.
The balloon was inflated in the bottle!
Hot water or tea may be dangerous for children.
Please take care if you try the exam with your kids.
