Galvanic cell bridge zinc ions leave and anions enter the zinc half-cell. In the copper half-cell, the copper ions plate onto the copper electrode (reduction), taking up electrons that leave the external conductor. Since the Cu ions (cations) plate onto the copper electrode, the latter is called the cathode. Correspondingly the zinc electrode is the anode. The electrochemical reaction is: In addition, electrons flow through the external conductor, which is the primary application of the galvanic cell. As discussed under #Cell voltage, the emf of the cell is the difference of the half-cell potentials, a measure of the relative ease of dissolution
Electrode array resistance, particularly the contact resistance between the probe and the surface, which can be high. Assuming the material is homogenous, the resistivity is given by: Electrode arrays are widely used to measure resistivity in geophysics applications. It is also used in the semiconductor industry to measure the bulk resistivity of silicon wafers, which in turn can be taken as a measure of the doping that has been applied to the wafer, before further manufacturing processes are undertaken. Electrode array An electrode array is a configuration of electrodes used for measuring either an electric current or voltage. Some electrode arrays can