Metallic bonding: Difference between revisions
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* [[Covalent bond]] |
* [[Covalent bond]] |
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* [[Ionic bond]] |
* [[Ionic bond]] |
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* [[Burn the Priest]] |
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* [[System of a Down]] |
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== References == |
== References == |
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Revision as of 00:47, 20 April 2007
Metallic bonding is the bonding between atoms within metals. It involves the delocalized sharing of free electrons among a lattice of metal atoms. Thus, metallic bonds may be compared to molten salts.
Metallic bonding is the electrostatic attraction between the metal atoms or ions and the delocalized electrons, also called conduction electrons. This is why atoms or layers are allowed to slide past each other, resulting in the characteristic properties of malleability and ductility.
Metal atoms typically contain a high number of electrons in their valence shell compared to their period or energy level. These become delocalized and form a sea of electrons surrounding a giant lattice of positive ions.
The electrons and the positive ions in the metal have a strong attractive force between them. This means that more energy is required to negate these forces. Therefore metals often have high melting or boiling points. The principle is similar to that of ionic bonds.
Metallic bonding is non-polar, because for pure elemental metals and even for alloys there is no (or a very small) electronegativity difference among the atoms participating in the bonding interaction, and the electrons involved in that interaction are delocalized across the crystalline structure of the metal.
The metallic bond accounts for many physical characteristics of metals, such as strength, malleability, ductility, conduction of heat and electricity, and lustre.
Due to the fact that the electrons move independently of the positive ions in a sea of negative charge, the metal gains some electrical conductivity. It allows the energy to pass quickly through the electrons generating a current. Heat conduction works on the same principle - the free electrons can transfer the energy at a faster rate than other substances such as those which are covalently bonded, as these have their electrons fixed into position. There also are few non-metals which conduct electricity: graphite (because, like metals, they have free electrons), and molten and aqueous ionic compounds which have free moving ions. [1] [2] [3]
Metal atoms have at least one valence electron which they do not share with neighboring atoms, nor do they lose electrons to form ions. Instead the outer energy levels of the metal atoms overlap. They are similar to covalent bonds. [4]