Iodine is formed when $KI$ reacts with a solution of

$Cu^{2+}(aq.) + X^{-}(aq.) \xrightarrow{R.T.} CuX \downarrow + X_2$
$X$ cannot be

The number of ions from the following that have the ability to liberate hydrogen from a dilute acid is. . . . . . . .$Ti^{2+}, Cr^{2+}, V^{2+}$

Which transition metal reduces steam to evolve hydrogen?

Give examples and suggest reasons for the following features of the transition metal chemistry:
$(i)$ The lowest oxide of transition metal is basic,the highest is amphoteric/acidic.
$(ii)$ $A$ transition metal exhibits highest oxidation state in oxides and fluorides.
$(iii)$ The highest oxidation state is exhibited in oxoanions of a metal.

Transition elements with lower oxidation states act as........