I really need help with this problem. I need to know how to work it and the answer. I am trying to review all these problems and they do not have answers. 2. It requires 242.7 kJ/mol to fragment Cl2 molecules into Cl atoms. What is the longest wavelength (in nanometers) of light that has enough energy to cause this bond to break? Could you please explain this to me? I have the answer: 242.7 kJ/mol. Is this right? Thanks.