Answer:
Q = - 1.5 x 10⁻¹² Coulomb
Explanation:
While in the neutral state, the charge on the piece of purple plastic must be zero. So the net charge is due to the charge of the extra electrons. Therefore,
Q = ne
where,
Q = net charge on piece of purple plastic = ?
n = No. of extra electrons on piece of purple plastic = 9.31 x 10⁶ electrons
e = Charge on one electron = - 1.6 x 10⁻¹⁹ Coulomb
Therefore,
Q = (9.31 x 10⁶)(- 1.6 x 10⁻¹⁹ Coulomb)
Q = - 1.5 x 10⁻¹² Coulomb
