what is the meaning of conduction band in metals. best wishes.?

Answer 1

The conduction band is not really related to the energy levels of electrons in an atom. Instead, it is about how electrons behave in a crystal lattice.

If you think about it, when you try to get an electron to move through a solid, it is going to keep coming across nuclei that will stop it in its tracks or bounce it back. So how on earth does anything conduct?

The answer is that electrons behave like waves. So the crystal lattice behaves like a 3D diffraction grating. You will have seen 1D diffraction gratings splitting light into a spectrum. What this tells you is that photon of a given energy can go easily in one direction but not at all in another (the dark bands). The same applies - but more complicated - to the electrons in a crystal (metals are crystalline in structure).

You can think of it this way - in some directions the electron can wiggle around all the nuclei because the spacing is a multiple of its wavelength, in others it cannot.

Because electrons are no free to move as they please in a metal then the usual rule that their energy will vary with the square of their momentum does not apply. The band structure of a material shows how energy and momentum are related. It varies in different directions in the material.

Importantly, the band structure has a gap in it. This gap is the area where there is no momentum an electron can have to have a given energy (you can see why this exists above). The band below this gap is called the valence band. The band above is called the conduction band.

Because of the Pauli exclusion principle. no two electrons can have the same state (i.e. the same momentum/energy/spin relation). So the bands fill up from the bottom.

To conduct, it must be possible to add some momentum to an electron to make it move. You can see that if the valence band is full, then you have to give a lot of energy before you can change the momentum because there is a gap before you find a vacant state.

Materials with a full valence band and empty conduction band are insulators.

Materials with some electrons in their conduction band are conductors.

Answer 2

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Answer 3

When we draw energy level diagram for a single atom, the lines are discrete and well separated from each other.

But diagram for a metal or many number of molecules the diagram consists of a number of bands instead of single discrete lines. (similar to line spectra and band spectra of spectral lines)

I f an electron has the energy corresponding to a particular band called conduction band then it is free to move inside the metal.

Other words the band of energy levels corresponding to free electrons is called conduction band.

Answer 4

conduction band is that area in the electronic shell which has free electrons to conduct... for eg one sodium atom has 1 e in its conduction band.... this band helps in conduction of heat and electricity... the other area is the valence band which cant conduct....