Terminology
 used in describing Lewis structures of molecules
 Bond pairs: An electron pair shared by two
 atoms in a bond. 
 Lone pair: 
 An electron pair found solely on a single atom.  
 Single covalent bond - 
 
 Bond between two atoms when they
 shared 1 pair 
 Double covalent bond – 
 Bond between two atoms when they
 shared 2 pairs.
 Triple covalent bond – 
 Bond between two atoms when they
 shared 3 pairs.
 Lewis Structure, Stability,
 Multiple Bonds, and Bond Energies 
 Bond order 
  The stability of a covalent compound is related to the
 bond energy.
  The magnitude of the bond energy increases
 and the bond length 
 decreases in the order:  single bond > double bond > triple
 bond.
 Bond Energy order: single < double <
 triple
 
  Bond length
 order: single (1)
 < double (2)  < triple (3)