List of top Chemistry Questions on properties of d block elements asked in AIIMS

$\left[ Ni ( CO )_{4}\right]$ is a diamagnetic complex. All the electrons in the complex are paired.
The free gaseous Cr atom has six unpaired electrons. Half-filled s-orbital has greater stability.
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?
The aqueous solution containing which one of the following ions will be colourless? (Atomic number of $Sc = 21, Fe = 26, Ti = 22, Mn = 25$)
Which of the following compounds is coloured?

The basic character of the transition metal monoxides follows the order