An electroplating cell is operated at a constant current of 0.64 mA.
How many conduction electrons pass a given point in the connecting copper wires of the cell in a time of 1.25 hours1.25\text{ hours}1.25 hours? (The elementary charge e=1.6×10−19 Ce = 1.6 \times 10^{-19}\text{ C}e=1.6×10−19 C)
5.0×10155.0 \times 10^{15}5.0×1015
3.0×10173.0 \times 10^{17}3.0×1017
1.8×10191.8 \times 10^{19}1.8×1019
1.8×10221.8 \times 10^{22}1.8×1022
