Question

A plastic rod that has been charged to â14 nC touches a metal sphere. Afterward, the rod's charge is â1.0 nC . How many charged particles were transferred?
Express your answer using two significant figures.

Answer 1

Answer:

$N = 8.1 \times 10^{10}$

Explanation:

Initial charge on the rod is

$Q_i = 14 nC$

final charge on the rod is

$Q_f = 1 nC$

now the charge transferred from to the sphere is given as

$\Delta Q = Q_i - Q_f$

$\Delta Q = 14 - 1 = 13 nC$

now we also know that

Q = Ne

so number of particles transferred is

$N = \frac{\Delta Q}{e}$

$N = \frac{13 \times 10^{-9}}{1.6 \times 10^{-19}}$

$N = 8.1 \times 10^{10}$