Which of the following is a diamagnetic transition metal ion?

In the $3d$ series of the $d$-block elements,which element has the maximum atomic size?

The number of unpaired electrons in $Zn^{2+}$ is

Observe the following ions: $V^{2+}, Zn^{2+}, Cu^{2+}, Fe^{2+}, Fe^{3+}, Ti^{3+}, Sc^{3+}, Ti^{4+}, Ni^{3+}, Co^{3+}, Cu^+$. How many ions in the above list have zero magnetic moment?

Which pair of ions is colourless?

The valence shell electronic configuration of $Cr$ and $Cu$ atoms, respectively, are