Part A How many electrons make up a charge of -40.0mu C ?

To find the number of electrons that make up a charge of $-40.0\mu C$, we need to use the fact that the charge of a single electron is $-1.6 \times 10^{-19}$ Coulombs.<br /><br />The formula to calculate the number of electrons is:<br /><br />Number of electrons = Total charge / Charge of a single electron<br /><br />Given:<br />Total charge = $-40.0\mu C$ = $-40.0 \times 10^{-6}$ C<br />Charge of a single electron = $-1.6 \times 10^{-19}$ C<br /><br />Plugging in the values, we get:<br /><br />Number of electrons = $(-40.0 \times 10^{-6}$ C) / ($-1.6 \times 10^{-19}$ C)<br /><br />Simplifying the expression, we get:<br /><br />Number of electrons = $2.5 \times 10^{14}$<br /><br />Therefore, there are $2.5 \times 10^{14}$ electrons that make up a charge of $-40.0\mu C$.