Hi...My name is Deepak... Currently, I am pursuing my master's in computational chemistry from the Central University of Punjab. 


Deepak James

Through this course, Deepak takes you the chapter, Classification of Solids, of Class 12 NCERT Textbook. He discusses topics like properties of various solids, packing efficiency in solids,  imperfections in solids, along with its electric and magnetic properties.

CBSE Class 12

English

Classification of Solid States and Their Properties: Class 12 NCERT

Solid State

Physical Chemistry

Chemistry

Class 6-12

Become a topper in your school and ace your board exams by learning from best educators in the country

CBSE

CBSE (Central Board of Secondary Education)

Imperfections of solids

Reasons of imperfections: Fast or moderate crystallisation process

Defects are two types 

Point defect and line defect 

Types of point defect 

1. Impurity defects,  stoichiometric defects and non stoichiometric defects 

Stoichiometric defects 

Well known as thermodynamic defects 

Two types: Vacancy defect, interstitial defect

Interstitial defects are two types 

Frenkel defects and schottky defect 

Frenkel defect 

Show vacancy defect,  no change the density of solid,  large size of ions is required Eg: Zns

Schottky defect 

It's vacancy defect,  decrease the density of solid,  ions must be in same size Eg Back

2. Impurity defect 

In molten Nacl containing a little amount of Srcl2 is crystallised. In here Na2+ ions are occupied by sr2+

Non- stoichiometric defects 

Does not disturb the stoichiometry of the crystalline substance 

There are two types of defects 

1, metal excess defect 2. Metal deficiency defect 

Metal excess defects are two types 

a, Metal excess defect due to anionic vacancies 

Yellow colour of Nacl is due to F centres

2, Metal excess defect due to the presence of extra cations at interstitial sites 

Zno -----> zn2+ + 1/2 O2+2 e-

3. Metal deficiency Defect 

Solids which are difficult to prepare stoichiometric composition and contain less amount of the metal as compared to the stoichiometric proportion

Imperfections of Solids

Classification of solids

1, Crystalline solid 

Long range order

Regular shape

Anisotropic nature

High melting point 

Eg: Nail

2, Amorphous solids

Short range order 

Irregular shape

Isotropic nature 

Low melting point 

Special property of amorphous solid: pseudo solids Or super cooled liquids 

Eg: Rubber

Classification of Solids

Electric properties of solids 

Solids are classified into three types based on the electric conductivity 

They are conductor,  insulator and semiconductor 

Origin of conduction of electricity in metal

Due to the movement of electrons 

A.o+A.O= M.O M.O( with similar energy)  = Energy band

Two types of band 

Valence band - Highest occupied band with electrons 

Conduction band- Lowest occupied band

Energy difference  between valence band and conduction band is forbidden zone 

Semiconductor 

Lowest energy gap
Conductivity of semiconductor is proptional with temperature 
Two types of semiconductor 

N type and P type semiconductor 

To increase conductivity we add impurities 

Two types of impurities 

Electron deficient and electron rich impurities 

Electron rich impurities 

Pentavalent impurities,  formation of free electrin

Electron deficient impurities 

Trivalent impurities,  formation of holes

Applications 

Diodes, transistor

Electrical Properties of Solids

Crystal lattices and unit cells

Crystal lattice: Regular three dimensional arrangements of points 

14 types of three dimensional lattice - Bravais lattice 

Characteristics of crystal lattice

1, Each point on lattice is lattice point 

2,  Each point represent an atom, a molecule  or an ion

Unit cell: smallest portion of crystal lattice 

Six parameters: a, b, c ( length)  
and alpha,  beta, and gamma ( Angles) 

Unit cells are divided into primitive unit cells and centered unit cells.

Primitive unit cells: Constituent particles present at its corners

Centered unit cells are three types 

1. Body centered unit cells 

Constituent particle present at it centre 

2, Face centered unit cell

Particles at centre of each faces

End centred unit cell: particle present at the centre of two opposite faces

7 types of primitive unit cells: cubic,  Tetragonal,  orthorhombic,  hexagonal,  Trigonal, monoclinic and Triclinic

Crystal Lattice and Unit Cells

Magnetic properties of solids

Reasons: Angular and spin motion of electrons

Different types of magnetic materials based on magnetic property 

1. Paramagnetic substance 

Weakly attracted substance ,  presence of one or more unpaired electrons Eg; O2

2.Diamagnetic substance 

Weakly repelled to the magnetic material,  no unpaired electrons Eg: Water 

3.Ferromagnetic material 

Act as a permanent magnet, In the presence of magnetic field the magnetic domain pointed towards the field of magnetic Eg: Iron

4.Antiferromagnetic substance 

No magnetisam shows due to the random and opposite and equal orientation of domains 

Eg: Mno

5. Ferromagnetic material

Weakly attracted due to the parallel and antiparallel with unequal number 

Eg: Magnetite

Magnetic Properties of Solids

KNOWLEDGE IS POWER.
Graduate.JEE qualified 2016..
Trying to make learning easier than ever before..

Aman Jaiswal

This course has explanation of some topics of the chapter solid state. Remaining topics will be covered in module 2 of this course.

(Hindi) Solid State - Module 1

Surbhi Pandey

In this course, the educator discusses Solids in physical chemistry for class 12 students.

(Hindi) We Are Rigid: Class XII CBSE

Pursuing B. Tech undergraduate Medicaps University Indore | IT Student | programmer | Learner | 

Rishin Tiwari

Complete Chapter of Solid state according to Ncert and CBSE syllabus with proper explanation , examples and few important questions.

Class 12th Chemistry - Solid State

Educator,Storyteller, 'Podcast'-(kahaniya)
M.Phil(Chemistry),LLB

Soma Agrawal

This course will help in covering the basics of the chapter Solid State of class 12 NCERT Chemistry text book

Solid State: Class 12

IITian at your door step (IITB)
 mentor, social influencer
Teaching Chemistry 
Experience : 10 plus years 
in most reputed institutes of Ind

Dhirpal 

This course covers fundamental concepts of atomic structure and sufficient problems from basic up to advanced level to help you crack all kind of problems from this topic in competitive examination

Lessons

5 lessons • 49m

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Imperfections of Solids

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Classification of Solids

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Electrical Properties of Solids

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Crystal Lattice and Unit Cells

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Magnetic Properties of Solids