Hair-raising science
This will make your hair stand on end!
Safety
- Carefully review the general safety advice on the back of the box cover before starting the experiment.
- The Van de Graaff generator setup can affect the work of ICDs and pacemakers. Read the safety instructions before use.
- Read the "Working with Batteries" section of the safety guidelines carefully before proceeding.
- Disassemble the setup after the experiment.
Step-by-step instructions
Charged particles can move from the foil mold to the tinsel strips. Make sure each strip is in contact with the mold.
The identically-charged particles on both the strips and the mold repel each other. This causes the “hair” on the model to stand up!
Disposal
- Dispose of solid waste together with household garbage.
- Dispose of used batteries in accordance with local regulations.
Scientific description
In your experiments with the Van de Graaff generator, the molds 
, tinsel strips 
, and underlay must be metallic, but why? Remember, when you used your finger to remove electrons 
from areas of the plastic lid 
, those areas ceased to be electrified, and new electrons from neighboring areas did not spread out to fill the vacant space. Meanwhile, when working with metal, you managed to electrify all the molds due to friction at just one point!
In plastic , electrons' freedom of movement is very limited. They can only move slightly, and therefore they accumulate only in places of friction. Meanwhile, electrons in metals can move much more freely, and mutual repulsion causes identical charges to scatter throughout the accessible area. Therefore, you manage to electrify all the molds without rubbing them against anything. The upper axis 
is connected to the mold by a metal wire along which the charges move.
The same happens with the metallic strips that play the role of hair. They receive charges from the mold and begin to push off 
from it and from each other. Since they’re glued in place, they wind up standing on end.
