I have some questions here about Benzene. So the presence of one substituent in a benzene ring will affect the ease and position of any further substituent group, such like [itex]-CH_3,NO_2,Cl[/itex]. And it's known that the Ortho,para-directing groups or electron donating groups are ring activating, consists of single bond, and will make the benzene ring easier to be attacked. My question is, why is it that the -Cl group is electron donating? i thought it'll pull the delocalised electron in the ring and stabilise it?