Which iron ore is reduced in a blast furnace to obtain iron metal?

When a copper wire is left in silver nitrate solution,it is observed that the solution turns bluish green.
$(a)$ Explain the observation.
$(b)$ Write the balanced chemical equation to represent the change taking place.

Which metal is purified by the method of liquation?

What is the melting point of alumina $(Al_2O_3)$ (in $;K$)?

How many atoms of sulfur are present in one molecule of sulfur?

An alloy is