Fill in the blanks:
$(a)$ The ground state electronic configurations of $Cr$ and $Cu$ are .......... and ..........,respectively.
$(b)$ Transition elements exhibit certain characteristic properties due to partially filled $d$-orbitals.
$(c)$ The general electronic configuration of transition elements is .......... .

(N/A) The ground state electronic configuration of $Cr$ $(Z=24)$ is $[Ar] 3d^5 4s^1$ and for $Cu$ $(Z=29)$ is $[Ar] 3d^{10} 4s^1$.
$(b)$ Transition elements exhibit characteristic properties due to partially filled $d$-orbitals.
$(c)$ The general electronic configuration of transition elements is $(n-1)d^{1-10} ns^{1-2}$.