A stream of electrons, each with a kinetic energy of 450 eV , is sent through a potential-free region toward a potential barrier of "height" 500 eV and thickness 0.300 nm. The stream consists of 1×1015 electrons. How many should tunnel through the barrier? Pick the closest answer. The electron mass is 9.10938×10−31 kg. 6×104 8×107 4×105 7×106 4×107 1×106 8×109 7×104 9×105 3×103