F-block

 F-block

• The elements in which the last electron enters the f-orbital of the atoms are called f-block elements.

• General electronic configuration:- (n-2)f1-14 (n-1)d0-1ns²

• These elements are also called inner transition elements.

• It contain two period, name is Lanthanoids and Actinoids.

  Lanthanoids

• Lanthanum La (Z=57) series called lanthanoid series.

• It contains Cerium Ce (Z=58) to lutetium Lu (Z=71).

• These elements are represented by the general symbol Ln.

• This elements have also been  called rare earth elements.

• General electronic configuration of lanthanoid series :- [Xe]4f1-14 5d0-1 6s².

• Promethium is synthetic radioactive lanthanoid.

Actinoids

• Actinium Ac (Z=89) series called actinoids series.

• It contain thorium Th (Z=90) to Lawrencium Lr (Z=103).

• General electronic configuration of actinoids :- [Rn]5f1-14 6d0-1 7s².

• Most of the economics and are coloured for example U+3 = red, U4+ = green, UO22+ = yellow.