CHEM 151 Lecture Notes - Lecture 7: Octet Rule, Covalent Bond

• School: University of Arizona
• Department: Chemistry
• Course: CHEM 151
• Professor: kumirov

Document Summary

**in general, the most stable structures are those in which each atom forms as many bonds as unfilled electron states are available in their valence shells. **double bonds tend to be shorter than single bonds between the same atoms because of a stronger net attraction between bonding electrons and their atomic nuclei. Resonance: valence electrons are delocalized across more than one covalent bond. Electrons get delocalized " ke goes down, pe goes down. **net decrease in total energy stabilizes the molecule. Free radicals: have unpaired valence electrons and can be neutral or charged particles. Central assumption: the most stable spatial distribution of electron domains in a molecule will determine how its several atomic nuclei arrange in space. Resonance rules: 1) atoms do not move (fixed atom arrangement) (delocalization of e-) 2) only move electrons in double (or triple) bonds or lone pairs.