What is the longest wavelength (in m} of the EM radiation that can eject photoelectrons from a certain metal target, given that the binding energy is 6.81 eV? Exponential format with 3 SF. QUESTION 24 When ultraviolet light with a wavelength of 381 nm falls on a certain metal surface, the maximum kinetic energy of the emitted photoelectrons is measured to be 1.76 x 10-19 J. How much energy, in Joule, does an electron have to gain in order to escape from the metal surface? Exponential format with 3 SF.