The Hall coefficient R is defined as R = Ey / JxBz , where Jx is the current per unit area in the x direction in the slab, Bz is the magnetic field in the z direction, and Ey is the resulting Hall field in the y direction. Show that the Hall coefficient is 1/nq, where q is the charge of the charge carriers, –1.6 × 10–19 C if they are electrons. (The Hall coefficients of monovalent metals, such as copper, silver, and sodium, are therefore negative.)