Number of electrons per unit volume

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Homework Help Overview

The discussion revolves around the number of electrons per unit volume in conductors versus semiconductors, particularly focusing on how temperature affects this number in each material type.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the distinction between free/conduction electrons and bound electrons, questioning why the number of free electrons remains constant in conductors while it varies in semiconductors with temperature changes.

Discussion Status

Participants are actively clarifying concepts and definitions, particularly regarding the nature of free electrons in different materials. There is an ongoing exploration of how thermal energy influences electron behavior in semiconductors compared to conductors.

Contextual Notes

Some participants express confusion about the terminology used to describe electrons in conductors and semiconductors, indicating a need for further clarification on the definitions of free and bound electrons.

thereddevils
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Why is the number of electrons per unit volume , n fixed in a conductor regardless of the temperature while its not in semiconductors ??
 
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I think you mean number of free/conduction electrons.
In a semiconductor, electrons can promoted to the conduction band by thermal energy; i.e. by raising the temperature of the material. In a conductor, the number of free/conduction electrons is more or less at saturation, and heating the material does not produce any more.

Of course the total number of electrons in the material is not affected by temperature.
 
Stonebridge said:
I think you mean number of free/conduction electrons.
In a semiconductor, electrons can promoted to the conduction band by thermal energy; i.e. by raising the temperature of the material. In a conductor, the number of free/conduction electrons is more or less at saturation, and heating the material does not produce any more.

Of course the total number of electrons in the material is not affected by temperature.

thanks so free electrons and electrons are different ? I thought they are the same .
 
They are only "different" in that in any material some are free to take part in conduction and others are not.
Some are situated deep in the lower energy levels of the atom where they are strongly bound, while others are in the outer levels where they are weakly bound.
 

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