Q. Differentiate crystalline and amorphous materials?
(a)Crystalline solids: Those solids in which the, ions atoms or molecules in a definite regular repeated three dimensional pattern are called solids. Thus the atoms or molecules in crystalline solid are arranged just as the sliders do on the parade ground.
e.g.Calcite, rock-salt, quartz, sugar-mica, diamond etc.
(b)Amorphous solids: Those solids in which the constituent atoms or molecules are not arranged in a definite pattern, repeating in three dimensions are called amorphous solid or materials.
e.g.plastic, glass etc.
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Crystalline materials
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Amorphous materials
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(a) The constituent's ions or molecules in a given crystalline solid are arranged in a definite geometrical pattern.
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The constituent's atoms or molecules in these solids are not arranged in a regular definite geometrical pattern.
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(b) These have a definite external geometrical shape.
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These are not regular in their external shape.
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(c) These have a long range order of atoms or molecules.
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These do not have a long range order of atoms or molecules.
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(d) All the bonds among molecules in these solids are equally strong. The crystalline solids have a sharp melting point.
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Amorphous solid do not have a sharp melting point, because the weakest bond get reputed at lower temperature and stronger bonds get reputed at higher temperature.
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(e) These are anisotropic i.e. the bond of crystalline solids have directional properties.
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These solids sre isotropic as their physical properties are same in all direction.
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In crystalline solids the angles between the flat surfaces of the crystal are constant.
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These are super cooled liquid of high viscosity.
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