Question

5 Number of electrons Copper consists of atoms that each have 29 electrons and mass 1.06 x 10-25 kg. Copper has a density of 8.69 kg/m3 mo. Assume that the copper is electrically neutral. b) Suppose that electrons are removed from the copper so that it has a net charge of 5.0 x 10-9 C (this is a typical number for capacitors in electronic circuits). Determine the number of electrons that have been removed. c) What fraction of the total number of electrons in the copper were removed to give it charge 5.0 x 10-9 C?

Answer 1

We will be using the fact that charge on an electron = -1.602 x 10^-19C.

When you are removing electrons from a neutral atom, it leaves equal amount of positive charge on it. So, in part (b) you need to divide the total charge by the charge on a single electron to get the total number of electrons to be removed.

The detailed solution for each part is shown below -

het chatse = 5x10-9C So, numher 10 Lo 12