Question

Why are the lanthanides and the actinides given a separate position in the modern periodic table?

Answer 1

1. In the modern periodic table, elements are arranged in increasing atomic numbers.
2. Long-form of the periodic table contains 7 periods and 18 groups.
3. These groups are divided into three parts - The left portion (containing extremely electropositive metals), the Right portion (consisting of metals, non-metals, metalloids, noble gases), and the middle portion.
4. This middle portion is further sub-divided into transition and inner transition elements.
5. Out of these inner transition elements consist of Lanthanides and Actinides each comprising 14 elements and kept separately below the main body of the periodic table.
6. Lanthanides and Actinides have been placed separately in a periodic table because of their electronic configurations, properties, and convenience for keeping the periodic table organized.