CK-12 Physical Science Concepts - For Middle School

3.8. Bond Polarity http://www.ck12.org

2. If a covalent compound has polar bonds and more than two atoms, what determines whether the compound is
   polar?


3. Is water a polar compound? Why or why not?


4. Which of the following compounds are polar?
   a. BF 3
   b. NH 3
   c. CCl 4
   d. CHCl 3

Review

1. What are polar covalent bonds? Give an example.


2. Why are the covalent bonds in an oxygen molecule (O 2 ) nonpolar?


3. Carbon (C) atoms attract electrons a little more strongly than hydrogen (H) atoms do. The illustration below
   shows three covalent compounds containing only carbon and hydrogen atoms. Are the compounds polar or
   nonpolar? Explain.