here, we're told that the binding energy of electrons on a metal surface are 7. times 10 to the negative 19 jewels. If an outside energy source with 4.33 times 10 to negative jewels strikes the metal surface, what would be the kinetic energy of an electron Ejected electron. So just remember that your total energy, which is the photon, equals the binding energy plus your kinetic energy. The total energy of the photon comes from this outside energy source. So that's 4.33 times 10 to the negative. 17 jewels equals you're binding energy, which is 7.15 times 10 to the negative. 19 jewels plus the kinetic energy of the electron ejected. So subtract out 7.15 times 10 to the negative jewels from both sides. So when we do that, we're gonna get left the kinetic energy of the ejected electron. So the kinetic energy here equals 4.26 times 10 to the negative 17 jewels. So this would be the energy kinetic energy Energy of motion for that ejected electron