What specific unfilled orbital of the electrophile is involved in this reaction?

What is the best way to remeber the differences between Sn1, Sn2, E1 and E2 reations?

2) Draw the product of the following pericyclic reaction. light Show how you formed the product by addressing the following points: a) Is the reactant using its HOMO or LUMO to complete the pericyclic movement of pi electrons? Draw all the lobes of the p orbitals of the pi bonds and designate the signs on each orbital to show the number of nodes corresponding to your choice of HOMO or LUMO. b) Is the reaction proceeding via conrotatory or disrotatory rotation of the outer lobes? Show the direction of the movement of p orbitals by drawing arrows.

1. would you expect the relative rate of SE2 reactions to be faster or slower if a molecule of chlorine is used instead of bromine? Explain your reasoning? 2. why is the first step in an electrophilic aromatic bromination so much more endothermic than the first step in an electrophilic addition of alkene?