Diamond and Emerald are composed of which of the following respectively?

Which property is exhibited only by transition elements?

Identify the order in which the spin-only magnetic moment (in $BM$) increases for the following four ions:
$(I) Fe^{2+}$
$(II) Ti^{2+}$
$(III) Cu^{2+}$
$(IV) V^{2+}$

The electronic configuration of gadolinium (atomic no. $64$) is

Which one of the following has a magnetic moment of $1.75 \ BM$?

The higher oxidation states of transition elements are found to be in combination with $A$ and $B$,which are: