Due to the _____ used in the dry cell, the chemical reaction proceeds very slowly.
a metal nitrate solution 'a' is added to reddish brown metal 'b'. the metal present in 'a' is used for making jewellery and turns black in air, very thin foils of metal are used to decorate sweets. the compound 'c' formed on chemical reaction is blue in colour and metal present in 'a' is formed, identify 'a', 'b' and 'c' and write chemical reactions invovled.
_________ is a bluish-white metal used to make dry cells and electrodes.