diff. between crystalline and amorphous

 CRYSTALLINE SOLID

1. They have definite geometric shape
2. They have sharp melting point
3. They are anisotropic. 
4. They are true solids
5. They have definite heats of fusion
6. they undergo a clean cleavage.

 AMORPHOUS SOLID

1. They have irregular shape
2. They melt over a range of temperature
3. they are isotropic
4. they do not have definite heats of fusion.
5. they are pseudo solids or supercooled liquids.
6. they undergo an irregular cut

    USE OF AMORPHOUS SOLID

  

1. A large no. of plastic which are amorphous solid are being used in article of everyday life
2. Another well know amorphous solid is rubber which is used in making tyres .shoe soles etc.

       CLASSIFICATION OF CRYSTALLINE SOLIDS

1. Ionic solid 
2. molecular solid
3. covalent solid or network solid 
4. metallic  solid