Chemistry Why are there those two rows of elements below the periodic table? Asked by arwen46 12 years ago 6/26/2013 7:08 AM Last updated by anonymous 12 years ago 6/28/2013 1:19 AM
The f-block, usually offset below the rest of the periodic table, comprises the lanthanides and actinides. If they were actually in the periodic table it would make it ridiculously long.