Metallic and Electrolytic Conductors
All substances do not conduct electrical current. The substances, which allow the passage of electric current, are called conductors. The best metal conductors are such as copper, silver, tin, etc. On the other hand, the substances, which do not allow the passage of electric current through them, are called non-conductors or insulators. Some common examples of insulators are rubber, wood, wax, etc.
The conductors are broadly classified into two types, Metallic and electrolytic conductors.
|Metallic conduction||Electrolytic conduction|
|(i) It is due to the flow of electrons.||(i) It is due to the flow of ions.|
|(ii) It is not accompanied by decomposition of the substance.(Only physical changes occurs)||(ii) It is accompanied by decomposition of the substance. (Physical as well as chemical change occur)|
|(iii) It does not involve transfer of matter.||(iii) It involves transfer of matter in the form of ions.|
|(iv) Conductivity decreases with increase in temperature.||(iv) Conductivity increases with increases in temperature and degree of hydration due to decreases in viscosity of medium.|
The electrolyte may, therefore, be defined as the substance whose aqueous solution or fused state conduct electricity accompanied by chemical decomposition. The conduction of current through electrolyte is due to the movement of ions.
On the contrary, substances, which in the form of their solutions or in their molten state do not conduct electricity, are called non-electrolytes.