Final answer:
When a glass rod is rubbed against silk, electrons are removed from the silk. In this case, the glass rod is charged to +7.0 nC, which means 7.0 microcoulombs of charge have been added to the rod. To calculate the number of electrons removed or protons added, divide the total charge by the charge of an electron.
Step-by-step explanation:
When a glass rod is rubbed against silk, electrons are removed from the silk, not the rod. This is because the glass rod has a greater affinity for electrons due to its material composition.
In this case, the glass rod is charged to +7.0 nC, which means 7.0 microcoulombs of charge have been added to the rod. Since the charge is positive, electrons have been removed from the rod.
To calculate the number of electrons removed or protons added, we need to know the charge of a single electron. The charge of an electron is approximately -1.60 x 10^-19 coulombs. Hence, the number of electrons removed or protons added can be calculated by dividing the total charge by the charge of an electron.