Amorphous solid definition: amorphous solid is a substance which appears like solid but does not have perfectly ordered crystalline structure and no regular arrangement of constituent particles in structure is called amorphous solid, For example, glass, rubber, plastics, etc.
The word amorphous means no form. There are two types’ crystalline and amorphous solids
Amorphous solid have some mechanical properties which are commonly associated with the word solid. But, the amorphous solids are different from crystalline solids in many respects. So, amorphous solids are sometimes are called as pseudo solids.
What is amorphous solid?
Amorphous solid the natural tendency for most substances is to form crystalline solids when cooled below their melting points. But certain substances like, glass, tars and many organic polymers do not crystallize when cooled to the below their melting points, particularly when they are rapidly. Thus, these materials fail to achieve the order typical of crystalline solids. Such substances in a solid state are called amorphous solids.
1} The substances like glass, rubber, wood etc. are amorphous solids. These substances show some of the mechanical properties of solids, but do not occur in characteristic geometrical shapes.
2} The properties such as, mechanical strength, refractive index, electrical conductivity etc. of amorphous solids do not depend upon the direction. Thus, the amorphous solids are isotropic.
3} Amorphous solids do not show sharp melting points. Instead, they gradually soften on heating and finally start flowing like liquids. Thus, the amorphous solids may be considered super cooled liquids whose viscosity decreases as the temperature is raised. Super cooled liquids are also called glasses. Amorphous and crystalline solids
4} the amorphous solids when hammered show an irregular fracture in the direction of the force applied,
5} In amorphous solids, the nearest neighbours may be in nearly proper lattice positions but the next nearest neighbours may be in nearly proper lattice positions but the next nearest neighbours are more out of alignment with the lattice position. This shows that the amorphous solids have only short-range order. The absence of long-range order in amorphous solids bring them closer to liquids than to the crystalline solids.
Amorphous solids show irregular fracture when hammered. A common amorphous solid is glass. Amorphous examples glass, rubber, plastics.
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