Homework Help: Paper Rubbed with Wool/Fur/Silk

1. Dec 3, 2008

soulembracer

1. The problem statement, all variables and given/known data
What kind of charges will a sheet of paper have after it has been rubbed with wool or fur? with silk?

2. Relevant equations
none

3. The attempt at a solution
I have an idea about this, I'm just not definite with the answer. I know the paper is a good insulator if kept dry. Assuming that the paper is dry, rubbing it with wool (which is a better insulator) will separate the charges.

I've read from my book that when objects are given net charges by rubbing them against one another, both electrons and ions/charged atoms can be transferred from one object to another.

Here's where I'm confused, since both electrons and ions can be transferred, what (specifically) could be its kind of charged?

I guess the wool would have negative charges, the paper - positive charges. I just don't know if it's right, and how to justify that. And also, is it the same with silk?

Help
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution