Basic chemistry

  Conductors and non-conductors   ( a ) Non - conductor or insulator : Substances which do not allow electric current to pass through them are called non-conductors or insulators.examples - pure water, ice, glass, rubber etc. ( b ) Conductor :  Substances which allow electric current to flow through them are called conductors. Examples -Metals, Aqueous solution of acids, bases and salts, fused salts and impure water etc. Conductors are of two types : (i) Metallic conductors (ii) Electrolytic conductors or electrolytes. ( i ) Metallic conductors : The conductors which conduct electric current by movement of electrons without undergoing any chemical change are known as metallic conductors.Metals (Cu,Ag,Fe,Al etc), non metals (graphite) and various alloys and minerals are examples. (i i) Electrolytic conductors : Those substances whose water solution conducts the electric current and which are decomposed by the passage of current are called electrolytes. In this case, conduction takes pl