The importance of the electronegativity concept and the graph are strongly emphasized as vital for understanding chemical bonding and the other principles that are described later, and is referred to again repeatedly as each chemical concept is explained.
Several general points about electronegativity are emphasized:
Atoms with one or two valence electrons, such as sodium and potassium, have low electronegativity and lose their valence electrons easily, whereas atoms with five to seven valence electrons, such as nitrogen, oxygen, and fluorine, are highly electronegative and, additionally, tend to remove electrons from less electronegative atoms.
Electronegativity, Ionic & Covalent Bonds, Polarity, & Hydrogen Bonds
Ionic bonds are explained as occurring between atoms of opposite electronegativity (differences of 2 or more on the numerical electronegativity scale).
Once again, electronegativity can be used as a central concept to describe hydrogen bonds.
In the case of =C=O and H-C=C=, the oxygen bonded to the carbon has a partial negative charge, but the hydrogen has no charge because it is bonded to carbon, which has similar electronegativity to carbon.
In an attempt to quantitatively assess the effectiveness of an early and strong emphasis on electronegativity as a central integrative concept, first exam scores, which require knowledge of chemical bonding and chemical principles, were analyzed for the two classes in which I utilize this technique.
For BY 373, however, there was a significant improvement in exam 1 scores after the electronegativity emphasis was introduced (2000-2004 mean = 66.
Parr, who has developed a rival method for deriving electronegativity values, says the scientific community will eventually decide which definition of electronegativity reveals the most about chemical bonding.
Allen says he expects a rough reception for his idea because the concept of electronegativity is so central to modern chemistry.
Other characteristics of fluoropolymers determined by the suength of the C-F bond and the low polarizability and high electronegativity
of fluorine include soil resistance, insulating properties, and the ability to act as a gas barrier.