Structure of Metals
DOE-HDBK-1017/1-93
BONDING
The important information in this chapter is summarized below.
Types of Bonds and Their Characteristics
Ionic bond - An atom with one or more electrons are wholly transferred from one
element to another, and the elements are held together by the force of attraction
due to the opposite polarity of the charge.
Covalent bond - An atom that needs electrons to complete its outer shell shares
those electrons with its neighbor.
Metallic 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 neutral atoms undergo shifting in centers of their charge,
they can weakly attract other atoms with displaced charges. This is sometimes
called the van der Waals bond.
Hydrogen bond - This bond is similar to the molecular bond and occurs due to the
ease with which hydrogen atoms displace their charge.
Order in Microstructures
Amorphous microstructures lack sharply defined melting points and do not have
an orderly arrangement of particles.
Crystalline microstructures are arranged in three-dimensional arrays called
lattices.
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