Final answer:
Electrons have been removed from the glass rod to give it a positive charge of +8.0 nC, and approximately 5 million electrons have been removed.
Step-by-step explanation:
When a glass rod is charged to +8.0 nC by rubbing, electrons have been removed from the rod rather than protons being added. This is because in the process of charging by friction, materials typically exchange electrons; protons are tightly bound in the nucleus and do not get transferred during such processes.
To calculate the number of electrons removed, we can use the charge of a single electron, which is approximately -1.6 × 10⁻¹¹ Coulombs. The total charge of +8.0 nC (which is +8.0 × 10⁻¹ Coulombs) divided by the charge of one electron gives us the number of electrons removed:
Number of electrons = Total charge / Charge of one electron
Number of electrons = +8.0 × 10⁻¹ C / -1.6 × 10⁻¹¹ C
Number of electrons = -5.0 × 10⁶
The negative sign indicates that electrons have been removed, and we have approximately 5 million electrons that have been removed.