1. Inflate both balloons
so they are the same size. Tie a knot
in the neck of each balloon so that
the air does not escape.
2. Tie one
end of the string to one of the balloons.
tape, secure the free end of the string
to the edge of a table.
the second balloon by rubbing it with
the wool scarf.
the charged balloon near, but not
touching the hanging balloon.
the motion of the hanging balloon.
Sum it up!
Before rubbing, like all
materials, the balloons and the wool
scarf have a neutral charge.
This is because they each
have an equal number of positively
charged subatomic particles (protons)
and negatively charged subatomic particles
When you rub the second
balloon with the wool scarf, electrons
are transfered from the wool to the
rubber because of differences in the
attraction of the two materials for
The balloon becomes negatively
charged because it gains electrons
from the wool, and the wool becomes
negatively charged because it gains
electrons from the wool, and the wool
becomes positively charged because
it loses electrons.
When the negatively charged
balloon is brought near the neutrally
charged hanging balloon, the electrons
on the surface of the hanging balloon
move away because like charges repel.
This leaves the surface facing the
charged balloon more positive.
Since opposite charges attract,
the positive charge on the surface
of the hanging balloon is attracted
to the negative charge on the hand-held
balloon. This attraction is strong
enough to move the hanging balloon.