Is it possible to weigh air without the aid of sophisticated devices?

Yes, it is. You will need two balloons of equal shape and size, a thin 60cm stick, three 30cm strings, and a pin.

1. Firmly tie one of the 30cm strings in the middle of the stick.
2. Inflate the two balloons with equal amounts of air so that they are both the same size.
3. Knot the balloons with the remaining string and firmly tie one balloon at each end of the stick.
4. Slide the strings along the stick until the stick is perfectly leveled when lifted. Holding up the stick, insert the pin into one of the balloons and watch what happens: the balloon loses all of its air as soon as it is popped.
5. The other balloon, which is still full of air, weighs more than the popped balloon and this explains why the stick leans towards the side of the inflated balloon. If you pop the balloon that is still inflated, the “scale” will be leveled once again.

Other experiments:

• How do you collect fingerprints?
• How can you tell if an egg is fully cooked without actually breaking its shell?
• Is it possible to weigh air without the aid of sophisticated devices?
• Can warm water freeze faster than cold water?
• Can you put a pin through a balloon without popping the balloon?