Chapter 9.5 - Between the Extremes: Electronegativity & Bond Polarity

In reality, what are substances; ionic, covalent, or a mix?

A mixture of ionic and covalent bonds

What is electronegativity?

The ability of a bonded atom to attract shared electrons

How is electronegativity related to atomic size?

It is inversely related to atomic size

Which one is more electronegative: a nonmetal or a metal?

A nonmetal

What is the most electronegative element?

Fluorine

What is the second most electronegative element?

Oxygen

What is the least electronegative element?

Francium

What is the second least electronegative atom?

Cesium

What is a polar covalent bond?

It occurs when atoms bond that have unequal electronegativity, so one atom is pulling the shared electrons closer to it than the other

What are the two ways polar bonds can be notated?

With either a polar arrow or delta positive and delta negative

When does a nonpolar covalent bond occur?

When the atoms bonded have equal electronegativity.

What is the electronegativity difference?

The difference between the electronegativity values of the bonded atoms

How is electronegativity difference abbreviated?

EN

What is the partial ionic character of a bond?

How similar a bond is to an ionic bond based off of the change in EN for that bond

What does a larger change in EN mean for partial ionic character?

The partial ionic character is more like that of an ionic bond.

What is the partial ionic character scale, greatest to least?

Ionic, strong polar covalent, slightly polar covalent, nonpolar

What two things can you look at to determine partial ionic character?

The change in EN for the bond and the percent ionic character

What is percent ionic character?

A percentage of how ionic a bond is based off of the behavior of a gaseous diatomic molecule in an electric field

What percent ionic character value separates ionic bonds from covalent bonds?

50%

How does percent ionic character relate to the change in EN?

It is directly proportional

Does electron sharing occur to some extent, to no extent, or always in every bond?

To some extent

What is the change in EN value for a bond between a metal and a nonmetal?

Large

What is the change in EN for a bond between two nonmetals?

Small

What are the physical changes a substance undergoes based off of its change in EN

As the change in EN decreases, the physical state of the substance changes from a solid to a gas