1. Polar and Nonpolar Bonding
Covalent Bonding
Susan Baird
Dori Delaney
Cindy Rothwell
Ionic & Molecular Compounds

2. Polar and Nonpolar Bonding
It is a good idea to understand
Covalent Bonding, and Electronegativity
Before proceeding through this presentation.
Ionic & Molecular Compounds

3. Polar and Nonpolar Bonding
From your study into electronegativity you discovered the group 1 (IA) and group 2 (IIA) metals have the lowest electronegativity.
Group 16 (VIA) and 17(VIIA) nonmetals have strong electonegativities and attract valance electrons more strongly than any other elements.
Ionic & Molecular Compounds

4. Ionic & Molecular Compounds
Nonpolar Bonding
When two of the same elements bond they are called diatomic molecules, some examples of this are Hydrogen H2, Oxygen O2 and Nitrogen N2.
The atoms in these bonds would have the same electronegativities. This means that both atoms attract the shared electrons to that same extent.
This type of bond is known as a Nonpolar Covalent Bond.
Ionic & Molecular Compounds

5. Ionic & Molecular Compounds
Polar Covalent Bonds
Polar covalent bond are bonds in which electrons are unequally shared between two atoms.
Chemists have developed a scheme by which you can use the difference in electronegativities to predict the type of bond that will form between atoms of any two elements.
Ionic & Molecular Compounds

6. Periodic Table with Electronegativity
Periodic Table that lists the electronegativities of the elements.
Ionic & Molecular Compounds

7. Polar Covalent Bonds
By using a periodic table with the list of electronegativities of each element you can predict what kind of bond will form based on the difference between the electronegativities.
Type of Bond
Electronegativity Difference
Ionic
Greater then 1.7
Polar Covalent
Between 0.5 and 1.7
Slightly Polar Covalent
(refered to as Covalent)
Less then 0.5
Nonpolar Covalent
Ionic & Molecular Compounds

8. Polar and Nonpolar Bonding
Check out the following video
Ionic & Molecular Compounds

9. Polar and Nonpolar Bonding
Lets look at Fluorine and Potassium.
The electronegativity of Fluorine is 3.98 and the electronegativity of Potassium is 0.82
3.98 – 0.82 = 3.16
The difference of 3.16 is
much greater then 1.7
therefore this bond
must be Ionic.
Type of Bond
Electronegativity Difference
Ionic
Greater then 1.7
Polar Covalent
Between 0.5 and 1.7
Slightly Polar Covalent
Less then 0.5
Nonpolar Covalent
Ionic & Molecular Compounds

10. Polar and Nonpolar Bonding
Consider the case of two oxygen atoms.
Both atoms have an electronegativity of 3.44
3.44 –3.44 = 0
Therefore this must
be a nonpolar covalent
Bond.
Type of Bond
Electronegativity Difference
Ionic
Greater then 1.7
Polar Covalent
Between 0.5 and 1.7
Slightly Polar Covalent
Less then 0.5
Nonpolar Covalent
Ionic & Molecular Compounds

11. Polar and Nonpolar Bonding
Consider the bond between Carbon and Chlorine in the compound Chloroform (CHCl3)
The electronegativity of Carbon is 2.55 and the electronegativity of Chlorine is 3.16.
3.16 – 2.55 = 0.61
The electronegativity
difference is
between 0.5 and 1.7
therefore this must be
a polar covalent bond
Type of Bond
Electronegativity Difference
Ionic
Greater then 1.7
Polar Covalent
Between 0.5 and 1.7
Slightly Polar Covalent
Less then 0.5
Nonpolar Covalent
Ionic & Molecular Compounds

12. Polar and Nonpolar Bonding
Check out this video:
Ionic & Molecular Compounds

13. Ionic & Molecular Compounds
Practice Problem
For each of the following pairs of electrons, predict whether a bond between them will be nonpolar covalent, polar covalent or ionic.
Carbon and Fluorine
Oxygen and Nitrogen
Chlorine and Chlorine
Copper and Oxygen
Silicon and Hydrogen
Sodium and Fluorine
Iron and Oxygen
Manganese and Oxygen Periodic Table
Ionic & Molecular Compounds

14. Ionic & Molecular Compounds
Answers
Carbon and Fluorine Polar Covalent
Oxygen and Nitrogen Slightly Polar Covalent
Chlorine and Chlorine Nonpolar Covalent
Copper and Oxygen Polar Covalent
Silicon and Hydrogen Slightly Polar Covalent
Sodium and Fluorine Ionic
Iron and Oxygen Polar Covalent
Manganese and Oxygen Ionic
Ionic & Molecular Compounds

15. Polar and Nonpolar Bonding
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Ionic & Molecular Compounds