In linear-sweep voltammetry and related techniques, the empirical quantity defined by the equation $$\frac{i_p}{A\sqrt{\nu }{c}_{\text{B}}}(=\frac{j_p}{\sqrt{\nu }{c}_{\text{B}}})$$ where $i_p$ is the peak current, A is the area of the electrode-solution interface, $\nu$ is the rate of change of applied potential, and $c_{\text{B}}$ is the bulk concentration of the substance B whose reduction or oxidation is responsible for the peak in question.