Crystalline Solids Vs Amorphous Solids

Crystalline Solids	Amorphous Solids
The crystalline solids have definite characteristic shape.	The amorphous solids have irregular shape.
They have regular arrangement of the constituent particles. They are said to exhibit long range order.	They do not have any regular arrangement of the constituent particles. They may have short range order.
They have sharp and characteristic melting point.	They do not have sharp melting point. They gradually soften over a range of temperature.
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.
They have a definite and characteristic enthalpy of fusion.	They do not have definite enthalpy of fusion.
They are anisotropic i.e. their physical properties like mechanical strength, refractive index, electrical and thermal conductivity are different in different directions.	They are isotropic i.e. their physical properties are same in all directions.
They are true solids.	They are pseudo solids and super cooled liquids.
Examples – iron, silver, common salt, potassium nitrate etc.	Example – glass, rubber, plastics etc.

Addition Polymerization Vs Condensation Polymerization

Addition Polymerization	Condensation Polymerization
Monomer units contain double or triple bond (reactive site) which combine in succession to give a polymer.	Monomer units contain two or more functional groups which react with each other to undergo condensation.
Monomers add on to yield a polymer without elimination of any by product.	Monomers combine to form a polymer with elimination of small molecules like H2O, HCl, NH3, CH3OH.
It is a chain reaction.	It is an intermolecular reaction.
It involves free radical or ionic mechanism.	It follows the mechanism of condensation or esterification.
It leads to formation of homochain polymers.	It leads to formation of heterochain polymers.
Molecular weight of polymer is an exact multiple of monomeric units.	Molecular weight of polymer is not an exact multiple of monomeric units.
Generally, thermoplastics are obtained.	Both thermoplastics and thermosets are obtained.
High molecular mass polymer is obtained immediately.	Molecular mass of polymer increases steadily through the reaction.
Radical initiator, Lewis acid or base is required.	Mineral acids and bases are used as catalyst.
Addition polymers are formed quickly.	Reaction is completed in different independent steps taking a definite period of time.
Common examples are polythene, polypropylene, PVC etc.	Common examples are terylene, bakelite etc.