Why do alkenes prefer to undergo electrophilec addition reaction while arenes prefer electrophilic substitution reactions ? Explain.

Explanation

Both benzene and alkenes react with eletrophiles because of their exposed `pi-"electrons"` and form carbocations.

The carbocation formed by alkene combines with the muclephile to form the addition product.

If this happend to benzene, the nuclephile removes a proton form benzene carbocation to form substitution product as to maintain the aromatic character.