Bending Water

In this demo, you will get to see the effects of positive and negative charge in action (in this case negative charge).  This demo can be accompanied by giving the children some magnets and allowing them to try to touch the two ends with similar or opposite charge together.  Here is what you will need:

  • Balloons (already blown up and dry)
  • Water stream (can be from a sink or if you have access, burettes work wonderfully)

What you want to do is have the children rub the balloon against their hair for 30-45 seconds.  This transfers electrons onto the balloon surface giving it a negative charge.  When you place the balloon near a stream of water, the water should bend towards the balloon.  This is due to the fact that water is a polar molecule, meaning it has a positive side and a negative side.  The positive side of the water is attracted to the negative charge on the balloon, thus the stream will bend.  Show how a normal balloon does not effect the water stream and also how if you put the balloon too close to the stream and get it wet, the water will no longer bend.