Why are the lanthanides and actinides series situated at the bottom of the periodic table?
Answer (2)
They are in the f-block, as they have f-subshells. This is due to their electronic arrangement. Their electronic arrangement is such that: in lanthanides, 4f orbitals are filled before the 5d orbitals are filled, and in actinides, 5f orbitals are filled before 6d orbitals are filled. Two photos are attached to further explain this.
The lanthanides and actinides are located at the bottom of the periodic table because they fill the 4f and 5f orbitals, respectively. This placement maintains the table's structure and reflects their unique chemical properties, which are distinct from other elements. Their historical context and electron configurations contribute to their separation from the main body of the table.
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