Which metal does not give the following reaction $M +$  water or steam $ \to $oxide $ + H$ $\downarrow$

Which of the following compounds is not coloured ?

Cuprous ion is colourless while cupric ion is coloured because

Passing $H_2S$ gas into a mixture of $Mn^{+2}, Ni^{+2}, Cu^{+2}$ and $Hg^{2+}$ ions in an acidified aqueous solution precipitates

Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionization enthalpy

A first row transition metal with highest enthalpy of atomisation, upon reaction with oxygen at high temperature forms oxides of formula $\mathrm{M}_2 \mathrm{O}_{\mathrm{n}}$ (where $\mathrm{n}=3,4,5$ ). The 'spin-only' magnetic moment value of the amphoteric oxide from the above oxides is. . . . . . ..$\mathrm{BM}$ (near integer)

(Given atomic number: $\mathrm{Sc}: 21, \mathrm{Ti}: 22, \mathrm{~V}: 23$, $\mathrm{Cr}: 24, \mathrm{Mn}: 25, \mathrm{Fe}: 26, \mathrm{Co}: 27, \mathrm{Ni}: 28, \mathrm{Cu}: 29$, $\mathrm{Zn}: 30)$