The molecular orbitals of conjugated dienes, such as 1,3-butadiene, show a continuous overlap of p-orbitals along the chain of alternating single and double bonds, which allows for delocalization of π electrons across all the adjacent atoms involved. This conjugation results in a stabilization of the molecule due to the lower energy of the delocalized π electrons compared to localized π electrons in non-conjugated dienes. In contrast, non-conjugated dienes have isolated double bonds where p orbitals are not aligned in a continuous system, and thus their π electrons are localized within the individual double bonds, leading to higher energy and less stabilization.