A student provides insight on fractional-order rate laws. Bonds involving atoms with lone-pair electrons are weakened by electron-pair repulsion. Electronegativity differences between atoms make ionic dissociation (heterolysis) easier and radical dissociation (homolysis) harder, although Pauling’s definition of electronegativity makes the logic of the latter effect somewhat circular. The course transitions from free-radical reactions to ionic reactions by discussing solvent properties, in particular the electrostatic properties of alkyl halides and alkanes.