A metal sphere has a charge of +7.80μC. What is the net charge after 5.97E+13 electrons have been added to it?

Answer 1

charge= e*numbercharge

original number of electron deficincy on sphere: n=7.8E-6 * e where e is the charge on a single electron.

now add the charges (remember the charge on electrons is negative), so the net is the electron (extra or deficiency) on the sphere, convert that then to coulombs.