Online Class 12 Chemistry Notes- Unit 1- Band Theory of Solids

Band Theory of Solids: A quantum mechanical model of electrons in solids that predicts certain restricted ranges or the bands, for the energies of these electrons is called as Band Theory of Solids. It is also called as energy band theory of solids. The behavior of an electron in a solid (and hence its energy) is related to the behavior of all other particles around it. This is in direct contrast to the behavior of an electron in free space where it may have any specified energy. The ranges of allowed energies of electrons in a solid are called allowed bands. Certain ranges of energies between two such allowed bands are called forbidden bands—i.e., electrons within the solid may not possess these energies. The band theory accounts for many of the electrical and thermal properties of solids and forms the basis of the technology of solid-state electronics.

A useful way to visualize the difference between conductors, insulators and semiconductors is to plot the available energies for electrons in the materials. Instead of having discrete energies as in the case of free atoms, the available energy states form bands.

Important energy bands in solids

There is a number of energy bands in solids but three of them are very important. These three energy bands are important to understand the behavior of solids. These energy bands are

Valence band
Conduction band
Forbidden band or forbidden gap

Read complete chapter click Class 12 Chemistry Notes- Unit 1- Band Theory of Solids

For more chemistry notes, CBSE Class 12 Chemistry articles, video lectures, CBSE exam alerts, Syllabus, sample papers and NCERT solutions for Class 12th, log in with Takshila Learning.

Comments

Online cbse coaching class for 11 Mathematics

Online cbse Class 11 maths : Online coaching classes for 11 maths and for other subjects. We are here to solve students problem instantly, So that they can improve himself/herself. One to One Correspondence and Equivalent Sets Suppose the members of the family are dinning and plates are prepared on the table then there is a One to one correspondence between the set of family members and the plates prepared. We will indicate this correspondence by the symbol If each element of a set A is associated with one and only one element of a set B and each element of B is associated with one and only one element of set A, then the sets A and B are said to be in one to one correspondence. If both the sets are finite and if they are in one to one correspondence, it is obvious that they have the same number of elements. If two sets have the same number of elements, they are said to be equivalent sets. Using symbol, we write A B. Between two equivalent sets, a one to one corr...

Best Sample papers for Bank PO Exam Download

Sample papers for Bank PO Exam | Question Paper for Bank PO : Institute of banking Personnel Selection (IBPS) Department issued a Notification of IBPS PO 2017 exam announced in October month. IBPS Probationary Officer (PO) Online Application Form process will be begin from July 2017. This is a hard exam for all students so aware of its value. Large number of candidates will participate in this exam. So all candidates should prepare well for it. Check out IBPS, Bank PO Sample papers, Question Paper Pattern, SBI PO Syllabus , IBPS Syllabus and other IBPS PO Preparation 2017 This paper is identical to any Bank PO Question Paper Pattern. Check whole IBPS Bank “PO question paper” subject wise. IBPS (PO) Paper Pattern Analysis with Syllabus and main topics of IBPS Exam 2017. PO Question Paper Pattern, Bank PO sample Papers for IBPS Bank Exam IBPS PO Exam will be conducted at three levels 1st- PO Preliminary Exam 2nd- PO Mains Exam 3rd- PO Common ...

What is the difference between human and physical capital

Difference between human and physical capital Human capital refers to a worker's abilities, education, ability, and other attributes that influence his or her productive capacity and earning potential. Physical capital Presence of trade barriers lead to mobility restriction. Process of formation is economic and technical. Physical capital is separable from the owner. Possibility of trading physical capital in the market exists. Continuous use leads to depreciation. Financial statements are present. Human capital Culture and nationality lead to mobility restriction. Process of formation is conscious and social process. Human capital is not separable Services rendered by the human capital can only be sold. Ageing leads to the depreciation but it can be minimized up to some extent. Financial statements are absent. Click to know for Importance and Impact of human capital on economic growth Tag - class 9 social science , class 9 economics, Human capital meaning, school online classes

Takshila Learning - Online Tutorials

Search This Blog