1. Polarity Ch 6.2b

2.  Diatomic compounds share electrons equally.  Equal forces pulling on the shared electrons  What happens when atoms do NOT share electrons equally?  Unequal forces pulling on the shared electrons

3.  Electronegativity = Atom’s attraction for electrons  Larger value  stronger attraction  Electronegativity trends (attraction for electrons):  Right side of periodic table: high  Exception for noble gases (Group #8A) - none  Left side of periodic table: low  Top of a group: higher  Bottom of a group: lower

4. Polar Covalent Bond :  Determine by electronegativity  Higher electronegativity  partial negative charge  Lower electronegativity  partial positive charge.

7.  Shared electrons in a hydrogen chloride molecule spend less time near the hydrogen atom than near the chlorine atom.

8.  Non-polar covalent  Electronegativity difference is <0.5  Polar covalent  Electronegativity difference is >0.5 and <2.0 (Between 0.5-1.9)  Ionic bond  Electronegativity difference is >2.0

9.  Boron and Hydrogen  Electronegativities: B = 2.0 H = 2.1  Difference:   Potassium and Iodine:  Electronegativities: K = 0.8 I = 2.7  Difference:   Sodium and Chlorine  Electronegativities: Na = 0.9 Cl = 3.0  Difference: 

10.  Boron and Hydrogen  Electronegativities: B = 2.0 H = 2.1  Difference: 0.1  non-polar covalent  Potassium and Iodine:  Electronegativities: K = 0.8 I = 2.7  Difference:   Sodium and Chlorine  Electronegativities: Na = 0.9 Cl = 3.0  Difference: 

11.  Boron and Hydrogen  Electronegativities: B = 2.0 H = 2.1  Difference: 0.1  non-polar covalent  Potassium and Iodine:  Electronegativities: K = 0.8 I = 2.7  Difference: 1.9  polar covalent  Sodium and Chlorine  Electronegativities: Na = 0.9 Cl = 3.0  Difference: 

12.  Boron and Hydrogen  Electronegativities: B = 2.0 H = 2.1  Difference: 0.1  non-polar covalent  Potassium and Iodine:  Electronegativities: K = 0.8 I = 2.7  Difference: 1.9  polar covalent  Sodium and Chlorine  Electronegativities: Na = 0.9 Cl = 3.0  Difference: 2.1  ionic