sticky balloon
When the air is very dry rub an inflated balloon on a wool
sweater. Then put the balloon against the ceiling or a wall.
Leave go and it may stay in place.
If you don't have a wool cloth try rubbing the balloon on
cat's fur or against your own hair. Do this when your hair
is very clean and dry.
This works because electrons separate from the wool and
accumulate on the balloon giving it a negative charge. The
negative electrical charges push electrons in the wall away
leaving the surrounding area of wall with a positive charge.
That positive charge and the balloon's negative charge
attract each other, so the balloon sticks.
This like most other static electricity experiments works
best when the humidity of the air is less than 60 percent.
Moisture conducts the charges away rapidly. In most areas of
the world low humidity is found only indoors in the winter.