Ionisation of Air to Remove Static Electric Charges

Materials

1. Wool
2. PVC pipe or plastic comb
3. String
4. Lighter

Procedure

1. Hang the string from an elevated position. Leave the bottom end free.
2. Rub the PVC pipe with wool. This deposits negative charges, or electrons, onto the surface of the PVC pipe.
3. Place the side of the pipe that is rubbed near the string. You should notice the string being attracted  towards the PVC pipe.
4. Holding the PVC pipe still while attracting the string, light a flame using the lighter and place it in between the string and pipe. You should observe the string falling back to its original position.

Science Explained When air is ionised with the help of a flame, it serves as a conducting medium through which static electric charges can escape from a surface.