Lanthanides and Actinides are placed separately as the properties of these elements is quite different from the elements in Periodic Table.
Rare Earth elements or lanthanides are placed in the period 6 of the periodic table of Mendeleev. Actinoids are placed in the period 7 of the periodic table of Mendeleev.
The periodic table of elements is a chart that organizes the elements and emphasizes their shared traits and commonalities. All the known elements and their atomic number are on the periodic table.
f block elements (lanthanides and actinides) are placed below the periodic table
The first period is at the top of the table. It consists of hydrogen and helium. The bottom period is period 7.
There are two rows deprecated from periodic table because they have different properties.They are referred as lanthanides and actinides
Actinides
Lanthanides and actinides are placed below the periodic table because of their unique physical and chemical properties.
F-block
Actinides comprise of atomic number 90-103. They are placed at bottom of periodic table.
they are not placed from elements 57-70.
Rare Earth elements or lanthanides are placed in the period 6 of the periodic table of Mendeleev. Actinoids are placed in the period 7 of the periodic table of Mendeleev.
At the bottom of the Periodic Table
Lanthanides (elements with atomic number 57-71) and actinides (elements with atomic number 89 to 103) are placed at the bottom of the periodic table.
They are in the period 7 and in the actinides family.
In the periodic table :)
The periodic table of elements is a chart that organizes the elements and emphasizes their shared traits and commonalities. All the known elements and their atomic number are on the periodic table.
f block elements (lanthanides and actinides) are placed below the periodic table