The metallurgical process in which a metal is obtained in a fused state is called:

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ In an Ellingham diagram,the oxidation of carbon to carbon monoxide shows a negative slope with respect to temperature.
Reason $R:$ $CO$ tends to get decomposed at higher temperature.
In the light of the above statements,choose the correct answer from the options given below:

What should be the considerations during the extraction of metals by electrochemical method?

In the extraction of iron,the reaction which occurs at $900-1500 \ K$ in the blast furnace is:

Extraction of gold and silver involves leaching with $CN^{-}$ ion. Silver is later recovered by

In smelting,the substance added to combine with impurities to form a molten product is called what?