$\operatorname{Zr}\,(\mathrm{Z}=40)$ and $\mathrm{Hf}\,(\mathrm{Z}=72)$ have similar atomic and ionic radii because of :

The spin only magnetic moment value of $Cr(CO)_6$ is

The 'spin only' magnetic moment value of $\mathrm{MO}_4{ }^{2-}$ is . . . . . BM. (Where $\mathrm{M}$ is a metal having least metallic radii. among $\mathrm{Sc}, \mathrm{Ti}, \mathrm{V}, \mathrm{Cr}, \mathrm{Mn}$ and $\mathrm{Zn}$ ).

(Given atomic number: $\mathrm{Sc}=21, \mathrm{Ti}=22, \mathrm{~V}=23$, $\mathrm{Cr}=24, \mathrm{Mn}=25$ and $\mathrm{Zn}=30)$

Hydrated $C{u^{ + 2}}$ ion will be

Which of the will not form an amalgam

Which of the following statements are correct about $\mathrm{Zn}, \mathrm{Cd}$ and $\mathrm{Hg}$ ?

$A$. They exhibit high enthalpy of atomization as the d-subshell is full.

$B$. $\mathrm{Zn}$ and $\mathrm{Cd}$ do not show variable oxidation state while $\mathrm{Hg}$ shows $+\mathrm{I}$ and + $II.$

$C$. Compounds of $\mathrm{Zn}, \mathrm{Cd}$ and $\mathrm{Hg}$ are paramagnetic in nature.

$D$. $\mathrm{Zn}, \mathrm{Cd}$ and $\mathrm{Hg}$ are called soft metals.

Choose the most appropriate from the options given below: