Question

A glass rod that has been charged to +13.0 NC touches a metal sphere. Afterward, the rod's charge is +7.0 NC.How many charged particles were transferred?

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Answer 1

$$n=\frac{\Delta Q}{e}$$

$$n=\frac{13\cdot 10^{-9}-7\cdot 10^{-9}}{1.6\cdot 10^{-19}}=3.75\cdot 10^{10}$$