Work functions are typically given in units of electron volts, or eV. 1 eV equals 1.602 x 10^-19 J. Determine the minimum wavelength of light necessary to overcome the work function of the following metals ("minimum" implies that the excess kinetic energy, 1/2mv^2, is zero): Li, 2.90 eV; Cs, 2.14 eV; Ge, 5.0 eV.