Which among the following elements is a soft element as compared to others?

The yellow colour of chromate ion and orange colour of dichromate ion is due to

Determine whether the following statements are True $(T)$ or False $(F)$:
$(a)$ An element or its ion that does not have a completely filled $d$-orbital is considered a transition element.
$(b)$ $Sc$ is a transition element.
$(c)$ $Zn$ is a transition element.
$(d)$ The energy difference between $(n-1)d$ and $ns$ orbitals is high.

Ferrous ion changes to $X$ ion upon reacting with acidified hydrogen peroxide. The number of $d$-electrons present in $X$ and its magnetic moment (in $BM$) are,respectively:

How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.

Which pair of elements from the following has half-filled $d$-orbitals in their observed electronic configuration?