they are the lanthanide and actinide series of rare earths
The f-block elements are placed at the bottom of the periodic table because if they were placed where they belong the periodic table would be too big to fit on a normal sheet of paper.
The elements that are placed outside of the periodic table are called transactinides. These elements are usually placed in a separate row below the main table and are synthetic elements that do not occur naturally on Earth.
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.
The bottom section of the periodic table is for the lanthanides and actinides, which are also known as the inner transition metals. These elements are placed below the main body of the periodic table to keep it compact, as they would otherwise disrupt the table's organization.
f-block elements (lanthanides and actinides)
The gaps represented the elements which were not discovered. When the elements were invented, they were placed into these gaps.
The f-block elements are placed at the bottom of the periodic table because if they were placed where they belong the periodic table would be too big to fit on a normal sheet of paper.
The elements that are placed outside of the periodic table are called transactinides. These elements are usually placed in a separate row below the main table and are synthetic elements that do not occur naturally on Earth.
The lanthanides are a series of elements that are placed at the bottom of the periodic table. They are located in the f-block, specifically in the period below the main body of the periodic table. The lanthanides have atomic numbers 57-71.
At the bottom of the Periodic Table
If new elements are placed, then they would be appended in the periodic table. It won't disturb existing 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.
The bottom section of the periodic table is for the lanthanides and actinides, which are also known as the inner transition metals. These elements are placed below the main body of the periodic table to keep it compact, as they would otherwise disrupt the table's organization.
Metals are placed at the left. Non-metals are placed at right in periodic table.
The periodic table contain all chemical elements, placed in a rational order.
Actinides