How does electronegativity impact polarity of molecules?

Question

Olivia Anton · Accepted Answer

An atom's ability to draw electrons to itself is measured by its electronegativity; fluorine is the most electronegative element and francium is one of the least.

Higher electronegativity helps atoms take more control over shared electrons creating partial negative and partial positive regions that result in dipoles that cause polarity. Atoms high in EN tend to take electrons, and atoms low in EN tend to give up electrons.

The positive and negative areas of the molecule's outer atoms will determine the polarity of the molecule.

Olivia Anton · Answer

The bond that unites two atoms can become polarized due to differences in their electronegativity, but the relative orientations of the bonds also influence the polarity of the molecule as a whole. For example, #H_2# has two atoms that have the same electronegativity so it is non-polar, but #HF# is polar because the electrons are attracted to #F# more than to #H#. In #CF_4# each of the four #C-F# bonds is polarized because #F# is more electronegative than #C#, but the four bonds are symmetrically opposed to each other (pointed at the vertices of a regular tetrahedron), so that the polarity of the bonds exactly cancels out, and the molecule as a whole is non-polar.

Noah Aldrich · Answer

undefined Electronegativity is the measure of an atom's ability to attract electrons towards itself in a chemical bond. In a molecule, if there is a significant difference in electronegativity between the atoms forming the bond, the bond becomes polar. This results in an uneven distribution of electron density within the molecule, creating partial positive and partial negative charges on the atoms involved. Consequently, the molecule itself becomes polar. The greater the difference in electronegativity between the atoms, the more polar the bond and the molecule will be.