A metallic sphere has a charge of x nC A negatively charged

A metallic sphere has a charge of + x nC. A negatively charged rod has a charge of - y nC. When the rod touches the sphere, x* 10^9 electrons are transferred. What are the charges of the sphere and the rod now?

Solution

8*10^9 electrons are transfered from the rod to the sphere. Total charge of 8*10^9 electrons is (8*10^9)*(1.6*10^-19) C. That is equal to 1.28nC. After the charge transfer total charge on the rod is -(9-1.28)nC = -7.72nC. Total charge on the rod is (8 - 1.28) nC = 6.72 nC