3.3 Hybridization

LEARNING GOALS

After   Chapter 3.3,    you will    be  able    to:

Recall  the percentage  of  s   character   present in  a   given   hybridization   level,  such    as  sp^2

Describe    the relationship    between electron    density and resonance   structures

Identify    the hybridization   of  an  atom    within  a   complex molecule:

Carbon has the electron configuration 1s^22 s^22 p^2 and therefore needs four electrons to complete its
octet (2s^22 p^6 ). A typical molecule formed by carbon is methane, CH 4 . Experimentation shows that
the four σ bonds in methane are equivalent. This may seem inconsistent with what we know about
the asymmetrical distribution of carbon’s valence electrons: two electrons in the 2 s-orbital, one in
the px-orbital, one in the py-orbital, and none in the pz-orbital. This apparent discrepancy is
accounted for by the theory of orbital hybridization.

sp^3

Hybrid orbitals are formed by mixing different types of orbitals. Just as with molecular orbitals, we
can use advanced mathematics to merge three p-orbitals and one s-orbital. The result? As shown in
Figure 3.4, this forms four identical sp^3 orbitals with new, hybridized shapes.