Illustrate the salient aspects of ionic and metallic bonded crystals.
|
Properties
|
Ionic
|
Metallic
|
|
Bonding
Force
|
The bonds exist due electro- static force of attraction between positive and negative ions of different elements
|
The bonds exist due to electro- static force of attraction between the electron cloud of valence electrons and positive ions of same or, different metallic elements.
|
|
Bond Ionation
|
Ionic bond is most easily formed when one of the atoms has smaller number of valence electrons, such as the alkali metals and alkali earths (by transfer of electrons).
|
This type of bond is characteristic of the elements having small numbers of valence electrons, which are loosely held, so that they can be released to the common pool.
|
|
Conductivity
|
Low conductivity is the property of solids formed by ionic bonding.
|
Good thermal and electrical conductivity is the property of most of the solids formed by metallic bonding.
|
|
Mechanical
Properties
|
Solids formed have high hardness.
Ionic crystals tend to break along
Certain planes of crystals rather
Than to deform in a ductile fashion When subjected to stresses.
|
Solids formed mostly have good ductility.
|
|
Bond
Strength
|
These bonds are generally stronger than metallic bonds.
|
These bonds are generally less stronger than ionic bonds.
|