5.6 combining the LE and MO models

Question 1

why does the LE model not satisfactorily describe the actual e- distribution of some molecules?

Answer 1

resonance structures are used to show molecules that have “variable” e- pairing

Question 2

molecules that require the concept of resonance in the LE model can be more accurately described using which models?

Answer 2

combined LE and MO models

Question 3

in the combined LE and MO models, which bonds are localized and which are delocalized?

Answer 3

sigma are localized (aka “belong to particular atoms”)

pi are delocalized (aka “don’t belong to particular atoms”