QUICK QUIZ
Match each of the following descriptions with the lettered types of bonds below.Answers:COORDINATE COVALENT BONDS
In a coordinate covalent bond, the shared electron pair comes from the lone pair of one of the
atoms in the molecule. Once such a bond forms, it is indistinguishable from any other covalent
bond. Distinguishing such a bond is useful only in keeping track of the valence electrons and formal
charges. Coordinate bonds are typically found in Lewis acid-base compounds (see chapter 13 on
Acids and Bases). A Lewis acid is a compound that can accept an electron pair to form a covalent
bond; a Lewis base is a compound that can donate an electron pair to form a covalent bond. For
example, in the reaction between boron trifluoride (BF 3 ) and ammonia (NH 3 ):
1. Bonding between atoms with the same electronegativities
2. Bonding between atoms with small differences in electronegativity
3. Bond in which the shared electron pair comes from the lone pair of one atom
(A) Polar covalent bond
(B) Nonpolar covalent bond
(C) Coordinate covalent bond