Question

*Distinguish between crystalline solids and amorphous solids. Give examples.

OR

Distinguish between crystalline solids and amorphous solids.

Answer 1

	Property	Crystalline solids	Amorphous solids
i.	Shape	They have definite characteristic geometrical shape due to the orderly regular long range arrangement of constituent particles.	They have irregular shape and lack characteristic geometrical shape due to the short range orderly arrangement of constituent particles.
ii.	Melting point	They have sharp and characteristic melting point.	They do not have sharp melting point. They gradually soften over a range of temperature.
iii.	Cleavage property	When cut with a sharp edged tool, they split into two pieces and the newly generated surfaces are plain and smooth.	When cut with a sharp edged tool, they cut into two pieces with irregular surfaces.
iv	Heat of fusion	They have a definite and characteristic heat of fusion.	They do not have definite heat of fusion.
v.	Anisotropy	They are anisotropic, i.e., have different physical properties in different direction.	They are isotropic, i.e., have same physical properties in all directions.
vi.	Nature	They are true solids.	They are pseudo solids or super cooled liquids.
vii.	Order in arrangement of constituent particles	They have long range order.	They have only short range order.
eg.		Copper, silver, iron, zinc sulphide, common salt, potassium nitrate, etc.	Glass, rubber, plastics, etc.