Provide the primary differences (comparison) between Lanthanoids and Actinoids.

(N/A) The differences between Lanthanoids and Actinoids are as follows:
| Feature | Lanthanoids | Actinoids |
| :--- | :--- | :--- |
| $(1)$ | They are elements of the $4f$ series. | They are elements of the $5f$ series. |
| $(2)$ | Their general symbol is $Ln$. | Their general symbol is $An$. |
| $(3)$ | They consist of $14$ elements of $4f$ plus Lanthanum,totaling $15$ elements. | They consist of $14$ elements of $5f$ plus Actinium,totaling $15$ elements. |
| $(4)$ | Lanthanoids show greater similarity among themselves compared to transition elements. | Actinoids show less similarity among themselves compared to Lanthanoids. |
| $(5)$ | These elements primarily exhibit a single oxidation state $(+3)$. | These elements exhibit a wide range of oxidation states. |
| $(6)$ | The chemistry of these elements is simpler due to small changes in size and nuclear charge across the series. | The chemistry of Actinoids is much more complex due to the wide range of oxidation states and radioactivity. |