The percentage $(\%)$ of silver in the alloy German silver is:

Match List-$I$ with List-$II$ (Both having metallurgical terms):

List-$I$	List-$II$
$A$. Concentration of $Ag$ ore	$I$. Reverberatory furnace
$B$. Blast furnace	$II$. Pig iron
$C$. Blister copper	$III$. Leaching with dilute $NaCN$ solution
$D$. Froth floatation method	$IV$. Sulfide ores

Choose the correct answer from the options given below:

Give the correct order of initials $T$ or $F$ for following statements. Use $T$ if statement is true and $F$ if it is false.
$(i)$ Every mineral is an ore but every ore is not a mineral.
$(ii)$ Slag is a product formed during the extraction of metal by the combination of flux and impurities.
$(iii)$ Highly pure metals can be obtained by zone refining.
$(iv)$ Carnallite is an ore of magnesium and sodium.

Which of the following is correct?

Match the following processes in List-$I$ with their respective applications in List-$II$:

List-$I$	List-$II$
$A$. Van Arkel method	$P$. Purification of titanium
$B$. Solvay process	$Q$. Manufacture of $Na_2CO_3$
$C$. Bassemerisation	$S$. Reduction of copper
$D$. Hall-Herault process	$R$. Reduction of aluminium

Railway wagon axles are made by heating rods of iron embedded in charcoal powder. The process is known as