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

Which of the following is the formula of the iron ore haematite?

On which principle does the method of fractional distillation work?

Which of the following metals exist in their native state in nature?
$(i)$ $Cu$
$(ii)$ $Au$
$(iii)$ $Zn$
$(iv)$ $Ag$

By which method is aluminum metal obtained by the reduction of alumina?

Four groups are given linking a metal, its ore, and the chemical formula of the main component of the ore. How many of these are correct?
$(1)$ Iron - Magnetite - $Fe_{3}O_{4}$
$(2)$ Iron - Siderite - $FeS_{2}$
$(3)$ Copper - Copper glance - $Cu_{2}S$
$(4)$ Copper - Dolomite - $Al_{2}O_{3}$