How can I determine bond polarity?

Question

Wyatt Atkins · Accepted Answer

Take the difference between the electronegativity value of the 2 atoms in the bond

You'll need to take the difference between the electronegativity value of the two atom. Their bond polarity is determined according to the range it falls in:

Nonpolar covalent: Electronegativity difference < 0.5
Polar covalent: Electronegativity difference is 0.5 - 1.6
Ionic: Electronegativity difference >2
For electronegativity difference 1.7 - 2, it's
- polar covalent if both atoms are nonmetals
- Ionic if one of the atom is a metal
  *the ranges may vary slightly depending on which source is used as reference; do check with your school.
  
  Electronegativity values look like this
  Let's take a look at some examples.
  1. HF - electronegativity difference = 4.0 - 2.1 = 1.9, #:.#polar covalent
  2. CBr - electronegativity difference = 2.8 - 2.5 = 0.3 #:.#nonpolar covalent
  3. LiF - electronegativity difference = 4.0 - 1.0 = 3.0 #:.# ionic

Ellie Andrews · Answer

undefined Bond polarity can be determined by comparing the electronegativities of the atoms involved in the bond. If the electronegativity difference between the two atoms is significant, the bond is polar. The greater the electronegativity difference, the more polar the bond. Additionally, the geometry of the molecule and any lone pairs of electrons can also influence bond polarity.