Fructose

Electronegativity
How Badly Does an Element Want Electrons?
Electronegativity (EN) is the relative ability of a bonded atom of an element to attract the electrons
from another element participating in the bond. As with most aspects of chemistry, the EN of
an element is a direct result of its Atomic Structure. We shall discuss this relationship between
electronegativity and atomic structure at length in this section.
We have previously discussed the two most common forms of bonds between elements Ionic
Bonds and Covalent Bonds. In most actual chemical compounds, however, the type of bonding
that occurs between elements falls somewhere between these two extremes of Ionic and Covalent
Bonds.
There are some very real and common examples of true Ionic Bonds, and a number of true
nonpolar covalent compounds. However, the great majority of compounds have bonds that are
more accurately described as polar covalent bonds. These polar covalent bonds are partially ionic
and partially covalent as shown in the picture below.
Ionic - Covalent - Polar Covalent Bonds
However, a Polar Covalent Bond takes on certain aspects of both and an Ionic Bond and a Covalent
Bond in that the electrons are shared but one element attracts them more strongly than the other.
In the resulting polar covalent bond, a partial positive and partial negative charge is created at the
poles of bond thus giving the Covalent Bond some Ionic or Polar properties.
One of the most important concepts in chemical bonding is Electronegativity which is abbreviated
EN. More than 50 years ago the great American chemist Linus Pauling developed the most common
scale of relative EN values for the elements.
The Pauling values for EN are shown in the following two pictures.
Pauling EN Values
In an Ionic Bond the electrons are completely transferred from one element to the other. In a
covalent bond, in this case a nonpolar covalent bond, the electrons are fully and equally shared
between the two elements forming the bond.
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