Which of the following transition metal is used as a catalyst
Nickel
Cobalt
Gold
Both $(a)$ and $(b)$
For $d-$ block elements the first ionization potential is of the order
The oxoanion in which the oxidation state of the central atom is same as its group number in the periodic table is
$Cu(CN)_4^{2 - }$ is colourless as it absorbs light in
The "spin-only" magnetic moment [ in units of Bohrmagneton, $(\mu _B )$ ] of $Ni^{2+}$ in aqueous solution would be (At. No. $Ni= 28)$