What are f-block Elements and how to write EC

f-block Elements are those in which the last electron enters the f-orbital of the anti-penultimate shell. Here, we will discuss about the f-block elements.

What are f-block

  1. These are elements in which last electron enters any one of the 7 orbitals of their respective penultimate shell.
  2. General outer electronic configuration : (n – 2) f 0-14 (n-1) d 0-2 ns 2 where n= 6 – 7
  3. There are 2 series of f-block elements each containing 14 elements.
  4. Therefore, there are 28 f-block elements in the periodic table.
  5. They are placed at the bottom of the periodic table.
  6. The elements of the first series 58Ce – 71 Lu. It forms the sixth period and are Lanthanides. These all the members follow La and resemble closely with La. 4f orbitals are filled here.
  7. The elements of the second series 90 Th – 103 Lr It forms the seventh period. These are actinoids. These all the members follow Ac and resemble closely with Ac. 5f orbitals are filled here.
  8. All the actinoids are radioactive elements.
  9. All the f-block elements are the inner transition elements.
  10. 11 elements are transuranic elements which follow Uranium.

General characteristics of f-block elements

  1. f-block are heavy metals.
  2. These elements have high melting point and boiling point.
  3. They show variable oxidation states in their compounds.
  4. These elements form the compounds which are generally coloured.
  5. They form complexes.
  6. Most of the actinides are radioactive.
  7. f-block elements show the reactivity of actinides and have magnetic properties.
  8. When the atomic number of the f-block increases, the atomic radii decreases. This is Lanthanoid and actinoid contraction.
  9. They are highly electropositive and highly reactive.
  10. f-block placed separately to conserve the space in the periodic table.

Check out the post on what is d-block elements here :

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