The lanthanides are located at the bottom of the periodic table, separated from the main body and positioned below Lutetium (Lu). They are sometimes referred to as the rare earth elements, although they are not actually rare.

Here's a more detailed explanation:

* Period: They are located in Period 6.

* Group: They are not part of any specific group, but are typically placed alongside Scandium (Sc) and Yttrium (Y), which are also transition metals.

* Atomic Number: Their atomic numbers range from 57 (Lanthanum) to 71 (Lutetium).

Let me know if you'd like to know more about the lanthanides!