Solid State part 1

SOLID STATE

1.1 Introduction

              Solid is one of the three main states of matter, along with liquid and gas. Matter is the "stuff" of the universe, the atoms, molecules and ions that make up all physical substances. In a solid, these particles are packed closely together and are not free to move about within the substance.

              Solid :-  The matter which possess rigidity  and hence possesses a definite shape and volume ,are called Solid.

1.2 General Characteristics of solid

·         The constituent particles are very closely packed i.e., inter-molecular distance are minimum.

·         Inter-molecular force between molecules to be maximum.

·         Solid substance occupy fix space.

·         They have definite shape and volume

·         They possess rigidity

·         They have high density

1.3 Classification of solid

Solid are of two types

1.       Crystalline solid

2.       Amorphous solid

Crystalline solid: - A solid substance in which atom molecule or ion regular arrange on their three dimensional figure is called crystalline solid.

Ex:- sodium chloride , graphite and diamond, etc.

Amorphous solid  :- a solid  substance in which atom molecule or ion irregular arrange on three-dimensional figure that is called amorphous solid.

Ex:- glass, rubber, plastic , all polymer ,etc.

1.4 classification of crystalline solid

   

Ionic solid  :- A solid substance which is formed by complete transformation of element that is called Ionic solid.

Ex:- NaCl , KCl , MgO , CaCl2 ,etc.

Covalent or Network solid:-  A solid substance which is form by sharing of electrons and have  a continuous network extending structure that is called Covalent or Network solid.

Ex:- Diamond, Graphite, Quartz, etc.

 

Metallic Solid :- Those type of solid substance which is form by attraction between metal to metal that is called Metallic Solid. These bonds are like huge molecular orbitals that span across the whole solid. This means the electrons in metallic solids are .delocalized.

Ex:- all metals and alloy.

Molecular Solid :- A solid substance which is formed by sharing of two or more than two electrons of same and different atoms that is called Molecular solid. (molecular solid’s structure are not like network).          

  Ex:- O2 , CO2 ,H2O , NH3 ,N2, etc.

 

1.5 Crystal lattices and unit cell

Crystal lattices: - The regular repeating of 3-D figure, is called Crystal lattices.

·         Some character of crystal lattices

1.       Crystal lattices are in 3-D figure.

2.       All points in crystal lattice is called lattice.

3.       Particles are present on each lattice point.

Unit cell :- The small part of crystal lattice which is in 3-D figure that is called Unit cell.

OR

The smallest group of atoms which has the overall symmetry of a crystal, and from which the entire lattice can be built up by repetition in three dimensions.

Type of Unit Cell :-  On the basis of axial angle and edge length unit cell or crystal system are of 7 types.

Type of unit cell on the basis of lattice point.(for Cubic)

1.      S.C.C. (Simple Centre Cubic unit cell):- Four lattice point on four corners.

2.      Centre cubic unit cell

• E.C.C.(end-centered unit cell) : an extra lattice point is centered in each of two opposing faces of the cell
• F.C.C.(face-centered) : an extra lattice point is centered in every face of the cell
• B.C.C.(body-centered) : an extra lattice point is centered in the exact middle of the cell

 

1.6 Number of atom in SCC , BCC , and FCC

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