Section 1
Evidence for Electric Forces: The Observational Facts
What is the total charge of 1 mole of electrons?
You are given a container with $5.0 \mathrm{g}$ of hydrogen atoms. What is the total charge on the electrons in the container? What is the total charge on the protons?
A piece of amber is charged by rubbing with a piece of fur. If the net excess charge on the fur is $+8.5 \mathrm{nC}\left(+8.5 \times 10^{-9} \mathrm{C}\right),$ how many electrons were added to the amber?
Approximately how many electrons are in your body? What is the total charge of these electrons?
What is the net charge on an object that has an excess of 45 electrons?
Approximately how many electrons are in a penny? Assume the penny is made of pure copper.
The excess charge per unit area on a surface is $\sigma=-5.0 \times 10^{-3} \mathrm{C} / \mathrm{m}^{2}$. How many excess electrons are there on a $1.0-\mathrm{mm}^{2}$ piece of the surface?
The charge per unit length on a glass rod is $\lambda=-7.5 \mu \mathrm{C} / \mathrm{m} .$ If the rod is $2.5 \mathrm{m}$ long, how many excess electrons are on the rod?
What is the net charge on a $\mathrm{Ca}^{+2}$ ion?