Question

How many electrons must be removed from an electrically neutral silver dollar to give it a charge of +3.5x10^-6C?

Answer 1

Answer:

$2.19\cdot 10^{13}$

Explanation:

The electron is a fundamental particle, with a charge of

$e=-1.6\cdot 10^{-19}C$

which is also known as fundamental charge.

For an object having N excess electrons, the total charge on the object is

$Q=Ne$ (1)

where e is the charge of the electron.

For the object in this problem, its charge is

$Q=+3.5\cdot 10^{-6} C$

This can be obtained by removing a negative charge equal to

$Q=-3.5\cdot 10^{-6}C$

Substituting into (1) and solving for N, we can find the number of electrons:

$N=\frac{Q}{e}=\frac{-3.5\cdot 10^{-6}}{-1.6\cdot 10^{-19}}=2.19\cdot 10^{13}$