Determine whether the following statements are True $(T)$ or False $(F)$:
$(a)$ Actinoid contraction is greater than lanthanoid contraction.
$(b)$ Actinoids are elements of the $4f$ series.
$(c)$ All actinoid elements have a $7s^2$ configuration.

(A) True $(T)$: The shielding effect of $5f$ electrons is poorer than that of $4f$ electrons,leading to a greater contraction in actinoids compared to lanthanoids.
$(b)$ False $(F)$: Actinoids are elements of the $5f$ series,not the $4f$ series.
$(c)$ True $(T)$: All actinoids have a $7s^2$ electronic configuration,while the $5f$ and $6d$ orbitals are progressively filled.