Conduction of Electricity in Metals

 

A conductor may conduct electricity through movement of electrons or  of  Electricity to the latter. 

Metals conduct electricity in solid as well as molten state. 

The conductivity of metals depend upon the number of valence electrons available per atom. 

The atomic orbitals of metal atoms form molecular orbitals which are so close in energy to each other as to form a band. 

If this band is partially filled or it overlaps with a higher energy unoccupied conduction band, then electrons can flow eastly under an applied electric field and the metal shows conductivity (Fig.)

If the gap between filled valence band and the next higher unoccupied band (conduction band) is large, electrons cannot jump to It and such a substance has very small conductivity and it behaves as an insulator (Fig.).