stats of matter

Solid, liquid and gas are three physical states of matter: They are inter converteable

Character istics of solid state :

 l) The solid of fixed composition has defined mass, volume, shape and density.

2) Solids have more density than liquid and gasesous state of the same matter (except ice )

3) Most of the solids are hard, incompressible and rigid. ‘

4) Intermolecular forces of attraction in solid state is strong.

S) In solid state molecules have no freedom.

6) All pure solids have characteristic melting point.

Classification of solids :

Solids are of two types

                   1) Crystalline solid                   2) Amorphous solid

1) Crystalline solid : A homogeneous solid in which the constituent particles like atoms, ions or mol

ecules are arranged in adefrnite repeating pattern through out the solid is called crystalline solid. e.g. NaCl, KN03, urea, sugar etc.

 2) Amorphous solid : A substance in which Igoo 'tuent particles are not arranged in a regular pattern

is called amorphous solid. Amorphous solids appear like solidsb tdo 0t have perfectly ordered crystalline structure.

e. g. glass, rubber, plastic etc.

Characteristics of crystalline solid :

1) They have a definite and ordering arrangement of the atoms, ions or molecules. 2) They have definite geometrical shape.

3) They consists of large number of tiny crystals called unit cells.

4) Unit cell is repeating structural unit and have definite shape and properties of the crystalline solid.

5) The forces in the crystalline solid may be ionic bonds, covalent bonds, hydrogen bonds or vander

Wall's force .

 6) It has long range order of regular pattern of arrangement which repeats in entire crystal.

7) they have  sharp melting point.

8) Crystalline solids show different physical properties in different directions, hence they are aniso tropic.

Characteristics of amorphous solids : 
1) They do not have regular arrangement of the atoms, ions or molecules.
2) They do not posses any definite geometrical shape.
3) The arrangement of constuent particles is to short range.
4) They do not have sharp melting point.
5) Physical properties do not change in directions hence they are isotropic.
6) They resemble the super cooled liquids.
7) When cut, they split into pieces with irregular and rough surface.