S2.1.2/2.2.1/2.3.1 - Predicting Bond Type

Deduce the polar nature of a covalent bond from EN values

Remember:

M + NM = ionic

NM + NM = Covalent

Metals-only = Metallic

Electronegativity Difference

• US Chemist Linus Pauling ( 1901 - 1994 )

  • Introduced idea of Electronegativity ($χ_p$) --> relative attraction that atom of an element has for shared pair of electrons in a Covalent bond.

  • Pauling Electronegativity Scale ( sec. 9 of booklet )

    • Shows Fluorine as most EN element w/ value of $χ_p=4.0.$ ( why ? )

• Main use: Estimating based on $\Deltaχ_p$, whether a bond is Ionic, Pure-covalent ( non-polar ) or polar covalent. This estimation is based on continuums and rules.