CHM 25500 Lecture Notes - Lecture 6: Lewis Structure, Electronegativity, Ketone
Document Summary
Chm 255 - lecture 6 - resonance and intro to alkanes. For some molecules, there are many possible valid lewis structures. It is not always possible to accurately represent a molecule using just one lewis structure. In reality, the structure of the molecule is a combination of multiple lewis structures. This type of molecule is known as a resonance hybrid. Curved arrows are used to indicate the rearrangement of electrons. Straight arrows between lewis structures indicate that both lewis structures contribute to the overall resonance hybrid. Only the position of electrons can be changed, not the position of atoms. Only pi bonding electrons and non-bonding electrons can be rearranged, all sigma bonds must stay in place. No more than 8 electrons may be in the valence shell of any given atom. The total number of valence electrons must stay the same. Some resonance structures contribute more to the resonance hybrid than others.