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

Lessons-Worksheets-Question Papers-CBSE Class 2 English

Lessons-Worksheets-Question Papers-CBSE Class 2 English CBSE 2nd Class English – One and Many In this blog, we share the spelling rules used in the concept of One and Many. When there is only one of a naming word (noun), it is said to be a singular noun . When a noun shows more than one, it is said to be in the plural . We can add –S, -es, -ves or ies to show that there is more than one noun. For example, we say many birds, four biscuits, six brushes. But for the students of Class 2 , it’s very difficult and confusing to understand where to use s , es, ves or ies in the form of many. Don’t worry, it looks difficult, but it is very easy as in grammar each concept has a set of rules that need to practice. Noun ending with –s, -x, -o, -sh, -ch, and –ss form plurals by taking –es. Look at these pairs of words: Bus – Buses Brush – Brushes Continue ..... Click here ...

Class 3 English Practice Grammar Worksheet -The Adverb

Class 3 English Practice Grammar Worksheet -The Adverb Class 3 English – The Adverb – Kinds of Adverb Fill in the blanks with suitable Adverbs of place. Choose from the box. Up outside everywhere back down away here there ...

Bhakti Movement NCERT Class 12 History

Bhakti Movement NCERT Class 12 History The Bhakti movement was an effort to achieve salvation and emancipation by devotion to God. In Hindi, the word bhakti refers to fervent devotion to God. This movement, which stressed a single-minded, ardent devotion to God, is seen as the most characteristic act of religious progress during the Middle Ages. In the 12th and 13th centuries, Kabir Das was a key figure in the Bhakti Movement. As a result of the movement, Kabir Das' poems and religious writings attained widespread fame. Kabir Das was raised up by a Muslim family. However, his religious beliefs were influenced by his Hindu teacher Ramananda, who regarded Rama as the highest God. The first Sikh guru and the founder of Sikhism was Guru Nanak. He vehemently opposed prejudice based on customs, rivalry, and caste in religion. Nanak was raised in a Hindu household and from an early age began to exhibit spiritual tendencies. He helped the indigent and underprivileged. His followers began r...

Takshila Learning - Online Tutorials

Search This Blog