period
Period
The vertical "rows" are called Columns, and the horizontal "rows" are called Periods
They are called f-block elements. The first row elements are called lanthanides. The second row elements are called actinides.
This row of chemical elements is a "period".
Elements in the first row of the rare earth elements of the Periodic Table are called LANTHANIDES.
you may think i am kidding but the horizontally aligned elements are called periods. The vertical is called groups.
row
row or column
litium, and elements in the 2nd period (row) are pretty common
A horizontal row on the periodic table of elements is called a period.
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.
Periods :P