Can non metal conduct electricity?if yes ,how?if no, why?
NO, they cannot conduct electricity.
Because they have no Free mobile electron. We all know that in solid electrons are carrier of electricity while ions are carrier in liquids.but note that some non-metal can conduct electricity like graphite an allotrope of carbon.
Firstly, there are non metals that can conduct electricity (ionic compounds), except they have to be dissolved to do that. One example is the salt used for cooking (NaCl in chemical formula). When dissolved, the ions are able to move freely and conduct electricity. Otherwise, like other non-metals, the particles are held in the structure and able to move freely, resulting in non-metals being unable to conduct electricity. Although metals are also held in a structure, they have free moving ions that can conduct electricity throughout the metal, allowing it to conduct electricity.
most of the non metals do not conduct electricity but there are some exceptions like graphite, Silicon-semi-conductor and metalloids(also semiconductors).
electrical conductivity in metals is due to the presence of free electrons which are absent in non metals.By free(free to move) electrons we mean the electrons that are loosely bound to the nuclei.
We know that metals have bigger atomic radii compared to non-metals.This means that the outer-most(valence) electrons are at such a distance from the nucleus that they are not pulled as strongly as the nucleus of non-metal atoms would(due to their smaller atomic radii and higher values of electro-negativity).
Hence metal atoms have low ionization potentials ie. they can form ions easily and it is these valence(free to move) electrons that are responsible for conductivity in metal atoms.(electricity is flow of charge caused by a potential difference between two points)