Which kind of impurities are present in the ores? What are these impurities collectively known as?

State whether the following statement is true or false:
Those minerals which contain a very high percentage of a particular metal and from which the metal can be profitably extracted are called ores.

In the froth flotation process,which particles get wetted by turpentine and rise to the surface of the liquid mixture with the froth?

Why should metal sulphides and carbonates be converted to metal oxides during the process of metal extraction?

$A$ metal that exists as a liquid at room temperature is obtained by heating its sulphide in the presence of air. Identify the metal and its ore and give the reaction involved.

Which method is used for the purification of semiconductor metals?