positively charged and is called a cation. They are now referred to as ions, and
the bond or attraction between them is called an ionic bond. These ions do not
retain the properties of the original atoms. An example can be seen in Figure 11.
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A 1.7 or greater electronegativity difference between atoms will essentially form an ionic
bond.Figure 11. Two Representations of the Ionic Bonding of LiFThese ions do not form an individual molecule in the liquid or solid phase
but are arranged into a crystal lattice or giant ion molecule containing many such
ions. Ionic solids of this type tend to have high melting points and will not
conduct a current of electricity until they are in the molten state.
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Covalent bonds involve a sharing of electrons between atoms. Their electro-negativity
difference is between 0 and 0.4.Covalent Bonds
When the electronegativity difference between two or more atoms is 0 or very
small (not greater than about 0.4), the atoms tend to share the valence electrons in
their respective outer energy levels. This attraction is called a nonpolar covalent
bond. Here is an example using electron-dot notation and orbital notation: