The d-and f-Block Elements short notes are available in the below link.


Elements in which the last electron enters any one of the five d-orbitals of their respective penultimate shell are known as transition elements or d-block elements.

Their general electronic configuration is (n – 1)d1 – 10ns0 – 2.

Transition series: d-block consists of four transition series,

1st Transition series or 3d series 21Sc – 30Zn

2nd Transition series or 4d series 39Y – 48Cd

3rd Transition series or 5d series 57La, 72Hf – 80Hg

4th Transition series or 6d series 89Ac, 104Rf –112Cn

General characteristics:

Melting and boiling points– High due to strong metallic bonding

Enthalpies of atomization– High due to strong interatomic interactions

Ionization enthalpies– Generally increase from le_ to right in a series

Oxidation states– Variable due to the participation of ns and (n – 1)d electrons

Atomic radii– Decrease from left to right but become constant when the pairing of electrons takes place

Complex formation– Form complexes due to high nuclear charge and small size and availability of empty d-orbitals to accept lone pair of electrons donated by ligands.

d-and f-Block Elements

Colored compounds– Form colored compounds due to dd transitions

Magnetic properties: Transition metal ions and their compounds are paramagnetic due to the presence of unpaired electrons in the (n – 1)d-orbitals and it is calculated by using the formula, m = n n ( +2) where n is the no. of unpaired electrons.

Catalytic behavior Due to variable oxidation states and the ability to form complexes

Interstitial compounds Due to empty spaces in their lattices, small atoms can be easily accommodated

Alloy formation: Due to similar atomic sizes

Volumetric titrations involving KMnO4 are carried out only in the presence of dil. H2SO4 but not in the presence of HCl or HNO3 because HCl is oxidized to Cl2 and HNO3 is itself a strong oxidizing agent and partly oxidizes the reducing agent. H2SO4 does not give any oxygen of its own to oxidize the reducing agent.


Lanthanoids: the Last electron enters one of the 4f-orbitals. Cerium (at. no. 58) to lutetium (at. no. 71).

Actinoids: the Last electron enters one of the 4f-orbitals. Thorium (at. no. 90) to lawrencium (at. no. 103).

General electronic configuration: (n – 2)f 1 – 14 (n – 1)d0 – 1 ns2

Important Topics in Chemistry