No chemical reaction takes place when granules of a rusty-brown solid A are mixed with the powder of another solid B. However, when the mixture is heated, a reaction takes place between its components. One of the products C is a metal and settles down in the molten state while the other product D floats over it. It was observed that the reaction is highly exothermic.<b>(a) </b>What could the solids A and B be?<br> <b>(b)</b> What are the products C and D most likely to be?<br> <b>(c)</b> Write the chemical equation for the reaction between A and B leading to the formation of C and D. Mention the physical states of all the reactants and products in this equation and indicate the heat change which takes place.<br> <b>(d)</b> What is the special name of such a reaction? State one use of such a reaction.<br> <b>(e) </b>Name any two types of chemical reactions under which the above reaction can be classified.