German silver is an alloy of

In the equation: $M + 8CN^{-} + 2H_2O + O_2 \rightarrow 4[M(CN)_2]^- + 4OH^{-}$,metal $M$ is

What is the percentage of carbon in steel?

Which one of the following statements is incorrect?

Match the conversions in Column-$I$ with the type$(s)$ of reaction$(s)$ given in Column-$II$.

Column-$I$	Column-$II$
$A$. $PbS \rightarrow PbO$	$p$. roasting
$B$. $CaCO_3 \rightarrow CaO$	$q$. calcination
$C$. $ZnS \rightarrow Zn$	$r$. Carbon reduction
$D$. $Cu_2S \rightarrow Cu$	$s$. self reduction

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.