Why is it that when you rub to objects together the negative charges will always go to one but not the other.?

Question

Example: if you rub a comb in ur hair, the comb will always recieve the negative charges and the hair always gives them.

Answer 1

It has to do with what the objects are made of and what their valence electron configuration is. Some materials have electron configurations that become more stable if they pick up an electron and some become more stable if they lose an electron. If you rub two such materials together, the friction is enough energy to cause the electrons to jump from one to the other because they were inclined to do that anyway. It is a difficult concept if you have not studied your periodic table.