Which of the following groups of transition metals is known as coinage metals?

In the following pairs,the one in which both transition metal ions are colourless is

The maximum and minimum melting points of the first and second transition series elements,respectively,are obtained with $-$

The correct order of $E^{\circ}_{M^{2+}/M}$ values for the four successive elements $Cr$,$Mn$,$Fe$,and $Co$ is:

Which of the following elements forms a coloured compound in its respective oxidation state?

Why do ions of the first transition series exhibit paramagnetism? State the calculated and experimental observed magnetic moments of these ions.