In the $3d$ transition series,as the atomic number increases,the paramagnetic character:

The metal ion (in gaseous state) with the lowest spin-only magnetic moment value is .... .

Which of the following ions has the maximum magnetic moment?

The valence shell electronic configuration of $Cr^{2+}$ ion is

Determine whether the following statements are True $(T)$ or False $(F)$:
$(a)$ Transition elements contain $d$-orbitals.
$(b)$ Ions of transition elements contain incompletely filled $d$-orbitals.
$(c)$ Only elements with completely filled $3d$ orbitals are considered transition elements.
$(d)$ Only elements that have incompletely filled $d$-orbitals in their ground state as well as in their ions are called transition elements.

Which of the following metals make the most efficient catalyst?