Solids have definite mass, volume and shape due to the fixed positions of their constituent particles. Amorphous and crystalline  are two types of solids. 
Amorphous vs Crystalline solids
Amorphous and crystalline solids differ  in the properties such as cleavage property, melting point, shape, anisotropy etc. 

Amorphous solids

1. There is only a short  range order in amorphous solids
2. Amorphous solids do not have a sharp melting point; they are softened in a range of temperature.
3. Amorphous solids undergo irregular or conchoidal breakage.
4. Amorphous solids are isotrophic-the properties will be independent of the direction in which they are measured.
5. Less rigid.

Examples of Amorphous solids: Fibre glass, Cellophane, Teflon, Polyurethane, Naphthalene, Polyvinyl chloride


Amorphous structure of a glassy solid  and lattice structure of a crystalline solid
Amorphous structure of a glassy solid (left) and lattice structure of a crystalline solid (right).

Crystalline solids
1. There is a long range order in crystals.
2. Melt at a sharp temperature.
3. Crystalline solids can be cleaved along definite planes.

4. Crystalline solids, in general are anisotrophic (It means that, their properties such as electrical conductivity, refractive index, thermal expansion etc. will be different directions).

5. More rigid.



Examples of Crystalline solids: Copper, Potassium nitrate, Benzoic acid

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