Which among the following cations will not form coloured compounds? (Atomic number $Cu=29, Ti=22, V=23, Mn=25$)

Four successive members of the first series of the transition metals are listed below. For which one of them is the standard electrode potential $(E^o_{M^{2+}/M})$ value positive?

Out of $Cu_2Cl_2$ and $CuCl_2$,which is more stable and why?

$A$ metal $M$ has the electronic configuration $M: 1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$. To which block does this metal belong?

Which of the following pairs of ions have the same paramagnetic moment?

Which of the following has the maximum number of unpaired electrons?