What is forbidden energy ( ) or band gap?
A. Forbidden energy gap is the difference of energy levels of conduction band and within
conduction band.
B. Forbidden energy gap is the difference of energy levels of conduction band and valence band.
C. when there is no energy
D. conduction band
Answer
Verified
453.3k+ views
Hint:The band gap can be thought of as the gap between electron energy levels or the
forbidden energy levels that cannot be occupied by the electrons. The energy levels which can be
occupied by electrons are conduction band and valence band. Therefore, the band is not the conduction band nor does it lie within the conduction band.
Complete step by step solution:
The group of discrete but closely spaced energy levels for the orbital electrons in the atoms is called as energy band gap. The energy bands are formed when the atoms are packed together as in solids.
The upper empty energy band is called as the conduction band and the lower completely filled energy
band is called as the valence band. In between the conduction band and valence band, there is a group of energy levels that cannot be occupied by the electrons. It is called as the forbidden energy ( ) or
band gap. That is, electrons are forbidden to occupy it. The electrons can jump from the valence band to the conduction band when they are excited by absorbing energy. Also, they can make a transition from conduction band to valence band by emitting energy.
The band gap can also be defined as the energy between the conduction band and the valence band. The electrons can either be in the valence band or they may jump to the conduction band skipping the energy levels of the band gap.
Hence, option (B) is the correct answer.
Note: The value forbidden energy ( ) or band gap differs for conductors, semiconductors and insulators. For conductors, the band gap may be negligibly small or zero. For insulators it may be very large and can range from to and semiconductors, the band gap is of the order of .
forbidden energy levels that cannot be occupied by the electrons. The energy levels which can be
occupied by electrons are conduction band and valence band. Therefore, the band is not the conduction band nor does it lie within the conduction band.
Complete step by step solution:
The group of discrete but closely spaced energy levels for the orbital electrons in the atoms is called as energy band gap. The energy bands are formed when the atoms are packed together as in solids.
The upper empty energy band is called as the conduction band and the lower completely filled energy
band is called as the valence band. In between the conduction band and valence band, there is a group of energy levels that cannot be occupied by the electrons. It is called as the forbidden energy (
band gap. That is, electrons are forbidden to occupy it. The electrons can jump from the valence band to the conduction band when they are excited by absorbing energy. Also, they can make a transition from conduction band to valence band by emitting energy.
The band gap can also be defined as the energy between the conduction band and the valence band. The electrons can either be in the valence band or they may jump to the conduction band skipping the energy levels of the band gap.
Hence, option (B) is the correct answer.
Note: The value forbidden energy (
Recently Updated Pages
How to find how many moles are in an ion I am given class 11 chemistry CBSE
Class 11 Question and Answer - Your Ultimate Solutions Guide
Identify how many lines of symmetry drawn are there class 8 maths CBSE
State true or false If two lines intersect and if one class 8 maths CBSE
Tina had 20m 5cm long cloth She cuts 4m 50cm lengt-class-8-maths-CBSE
Which sentence is punctuated correctly A Always ask class 8 english CBSE
Trending doubts
The reservoir of dam is called Govind Sagar A Jayakwadi class 11 social science CBSE
What problem did Carter face when he reached the mummy class 11 english CBSE
What organs are located on the left side of your body class 11 biology CBSE
Proton was discovered by A Thomson B Rutherford C Chadwick class 11 chemistry CBSE
Petromyzon belongs to class A Osteichthyes B Chondrichthyes class 11 biology CBSE
Comparative account of the alimentary canal and digestive class 11 biology CBSE