CHM 2353 Lecture Notes - Lecture 4: Ab4, Bond Energy, Trigonal Planar Molecular Geometry

• School: University of Ottawa
• Department: Chemistry
• Course: CHM 2353
• Professor: Muralee Murugesu

Document Summary

Covalent: electrons are shared by atoms in a compound. Metallic: electrons are delocalized throughout an entire crystal. Bonds form so that each atom will have 8 valence electrons. Lone pairs: pairs of electrons that do not participate in bonding. Bonding pairs: pairs of electrons that participate in bonding (shown as a line - shared electrons) Multiple bonds: shorter and stronger than single bonds. Single bond: two atoms share one pair of electrons. Double bond: two atoms share two pairs of electrons. Triple bond: two atoms share three pairs of electrons. Incomplete octet: hydrogen only needs 2 valence electrons, group 2a elements only need 4 valence electrons, group 3a elements only need 6 valence electrons. Expanded octet: periods 3 and beyond have d-orbitals, which allows an atom to have an expanded octet. Odd-electron molecules: nitrogen atoms are stable with an odd number of electrons. Count the valence electrons for each atom and the whole molecule.