What you need:
A small balloon (bigger ones won’t inflate much), an empty plastic water bottle (the larger the better; use a 1.25 or 2-litre one), two bowls, Hot water (not necessarily boiling hot), Ice water
What to do:
1. Fill one bowl with hot water and the other with ice water. Make sure you don’t fill them to the brim.
2. Uncap the bottle and cover its mouth with the balloon.
3. First, put the bottom of the bottle in the bowl with the hot water. Hold it in there for 30 to 40 seconds. Watch what happens to the balloon.
4. Now, transfer the bottle into the bowl of cold water. Hold it there for 30 to 40 seconds too.
What happens?
When the bottle is placed in the hot water, the balloon slowly inflates! It stays inflated for a bit even after it is removed.
Once the bottle is in the cold water bowl, the balloon deflates.
Why?
The bottle is full of air. When it is placed in the hot water, the air molecules inside the bottle heat up. This causes the air to expand, which means the air molecules start spreading out and taking up more space. That’s how they move into the balloon causing it to inflate.
Similarly, cold water cools down the air in the bottle. Once the air cools, it starts contracting, which means its molecules start moving back close to each other.
Thus, they no longer need the extra space in the balloon. The air moves back into the bottle and the balloon deflates.
Picture Credit : Google
