Due to covalent bonding,the transition metals are

Which of the following is ferromagnetic?

An ion which has $18$ electrons in the outermost shell is

What is the number of unpaired electrons in $f$ orbitals of lutetium in its $+3$ oxidation state?

Which of the metal ion will have the highest number of unpaired electrons?

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.