Polar Covalent and Ionic Bonds

polar-covalent bonds formed when:

when e- are shared unequally between two atoms

- unequal e- sharing causes one side of bond to be negatively charged

range of electronegativity difference in polar covalent bonds

0.4-2.0

dipoles

molecules containing polar bonds

find electronegativity difference

EN1 - EN2 where en1 > en2

electronegativity differences form:

a continuum showing the degree of sharing e- that occurs in a bond

bonds are ionic when:

difference in electronegativity is greater than 2.0, usually occur between metals and non metals

ionic bonds form:

very stable compounds with high melting points

ionic bonds

electrostatic attractions between ions occur and crystals form, results in decrease in potential energy and increase in generation of heat

resonance structures

used to represent molecules when no single electron dot structure adequately represents a molecule

- don't actually exist but when taken with other diagrams offers better representation than any one diagram