Hey,

For the general reaction Z + e- ---> Z-, where S is any element, change in H is most negative for which of the following elements? Li, Br, Cl, Ar, Kr. Answer: Cl

can someone explain this? Is it because Cl gets excited to noble gas status and gives off the most energy when it drops back down to is ground state?

thanks
a

hmm, i think if Cl gains an electron it will go to noble gas status, and since Cl is more electroneg than Br it is more favorable for it to happen......not sure though.