Which of the following ores is in the form of carbonate?

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.

How is copper obtained from $Cu_{2}S$? Give reactions.

Which of the following metals are obtained by electrolysis of their chlorides in molten state?
$(i)$ $Na$
$(ii)$ $Ca$
$(iii)$ $Fe$
$(iv)$ $Cu$

What is the percentage concentration of sodium hydroxide solution used in the Bayer process (in $\%$)?

Which ore is concentrated by the froth flotation process?