Structure of Metals
Metallic bond - In this type of bond, the atoms do not share or exchange electrons
to bond together. Instead, many electrons (roughly one for each atom) are more
or less free to move throughout the metal, so that each electron can interact with
many of the fixed atoms.
Molecular bond - When the electrons of neutral atoms spend more time in one
region of their orbit, a temporary weak charge will exist. The molecule will
weakly attract other molecules. This is sometimes called the van der Waals or
Hydrogen bond - This bond is similar to the molecular bond and occurs due to the
ease with which hydrogen atoms are willing to give up an electron to atoms of
oxygen, fluorine, or nitrogen.
Some examples of materials and their bonds are identified in Table 1.
The type of bond not only determines how well a material is held together, but also
determines what microscopic properties the material possesses. Properties such as the
ability to conduct heat or electrical current are determined by the freedom of movement
of electrons. This is dependent on the type of bonding present. Knowledge of the
microscopic structure of a material allows us to predict how that material will behave
under certain conditions. Conversely, a material may be synthetically fabricated with a
given microscopic structure to yield properties desirable for certain engineering