gcsescience.com 5 gcsescience.com
Neutral Objects.
We know that like charges repel and
unlike charges attract
but what about neutral (uncharged)
objects?
It is found that a charged object (whether positive or negative)
may attract uncharged objects,
for example a charged plastic comb
will pick up small pieces of paper.
You can try this yourself.
Just charge the comb by combing your
hair! (hair is a good
insulator).
What is happening?
It is thought that when a
negatively charged object
gets close to an uncharged one,
electrons in the uncharged object are
repelled,
leaving the positive charges
behind.
These positive charges are then
attracted to the negatively charged object.
If the rod was positively charged,
then it would attract electrons in the
neutral object
and so the two would still attract
each other
(just reverse the + and - in the picture above).
The small
number of charges shown is an
oversimplification
since in reality there are millions
and millions of atoms
in a
tiny piece of paper, each with its own electrons and protons.
When we draw the rod with a few negative
charges,
it means that the rod has a few
more negative than positive
charges.
Headings Electrostatic
Charge Search Questions 
gcsescience.com Contents Index Quizzes gcsescience.com
Copyright © 2008 Dr. Colin France. All Rights Reserved.