Properties common to the elements manganese, iron, cobalt, nickel and copper include the ready formation by them all of
$(I)$ coloured ions in aqueous solution
$(II)$ oxides of nitrogen are formed on reaction with concentrated $HNO_3$
$(III)$ chlorides of formula $MCl_2$ and $MCl_3$
$I, II, III$
$I, II$
$II, III$
$I$, only
Stainless steel is non-corrosive. This character is more prominent in
$Zn$ and $Cd$ metals do not show variable valency because
Identify the alloy containing a non-metal as a constituent in it.
The metal ion which does not form coloured compound is
Steel differs from pig iron and wrought iron in that it contains