CHEM 130 Lecture 4: Lecture 4
Document Summary
Resonance: a way to describe molecules and ions for which no single lewis structure provides a truly accurate representation, eg: carbonate ion, three lewis structures for the carbonate ion. Have the same number of valence electrons: 2. Obey the rules of covalent bonding: no more than 2 electrons in the valence shell of h, no more than 8 electrons in the valence shell of a 2nd period element. 3rd period elements may have up to 12 electrons in their valence shells: 3. Differ only in distribution of valence electrons: 4. Have the same total number of paired and unpaired electrons: examples of ions and a molecule best represented as resonance hybrids. Problem: nitrous oxide, n2o, laughing gas, is a colorless, nontoxic, tasteless, and odorless gas. 16 valence electrons (b) write two equivalent contributing structures for this molecule. Be certain to show formal charges, if any are present. (c) explain why the following is not an acceptable contributing structure.
