CHEM 1210 Lecture Notes - Lecture 3: Lewis Structure, Covalent Bond, Vsepr Theory
Document Summary
Many molecules and ions are best described by writing two or more lewis structures. These molecules or ions are said to exhibit resonance. Double-headed (resonance) arrows are placed between individual contributing structures. The molecule or ion is a hybrid of the various contributing structures. Obey the rules of covalent bonding (valid lewis structures) No more than 8 electrons in the valence shell of a 2nd period element and no more than 2 electrons in the valence shell of h. 3rd period elements (s and p) can have no more than 12 valence electrons. Differ only in distribution of valence electrons; the position of all nuclei (the atoms) must be the same. Have the same number of paired and unpaired electrons. Curved arrow: a symbol used to show the redistribution of valence electrons. The tail of the arrow identifies a pair of electrons whose location is changing.
