the actinide and lanthanide elements are found in f - block.
the actinide and lanthanide elements are found in f - block.
where are the actinide and lanthanide elements found?
f - block
this variant, which is stated in the 2005 "red book" to be the iupac-agreed version as of 2005 (a number of later versions exist, and the last update is from 1st dec. 2018), emphasizes similarities in the chemistry of the 15 lanthanide elements (la–lu), possibly at the expense of ambiguity as to which elements occupy the two group 3 positions below yttrium, and a 15-column wide "f" block (there can only be 14 elements in any row of the "f" block).









































section::::open questions and controversies.:group 3 and its elements in periods 6 and 7.:la-ac and lu-lr.
periodic table
seaborg's actinide concept of heavy element electronic structure, predicting that the actinides form a transition series analogous to the rare earth series of lanthanide elements, is now well accepted and included in the periodic table. the actinide series is the second row of the f-block (5f series), and comprises the elements from actinium to lawrencium. in both the actinide and lanthanide series, an inner electron shell is being filled.
history of the periodic table