Previous: Chapter 8

I. Polarity

A. Electronegativity - the ability of an atom to attract electrons

B. A molecule is polar if the difference in electronegativity is greater than or equal to 0.5 (unequal sharing)

1. It's non-polar if the difference is less than 0.5 (equal sharing)

2. E.g. HF is a polar molecule since fluorine has 4.0 electronegativity and hydrogen has 2.1 (1.9 difference)

a. In this case, the dipole arrow points to fluorine

C. In molecules with more than two atoms, it is non-polar if all terminal atoms are the same, the molecule is symmetrical and all dipole arrows cancel out

1. Dipole arrows cancel out when all arrows have the same strength and are all pointing in opposite directions

2. E.g. CF4 is non-polar as it meets all 3 criteria

II. Hybridizations

A. The mixing of atomic orbitals to form bonding orbitals

B. Types of hybridizations: SP, SP2, SP3, DSP3 and D2SP3

1. E.g. For N2, it has an SP hybridization