Chemistry > d and f Block Elements > 7.0 Lanthanoid Series
d and f Block Elements
1.0 General Introduction and Electronic Configuration
2.0 Occurrence and General Characteristics of Transition Elements
3.0 General Trends in properties of First Row Elements
3.1 Ionisation Enthalpy
3.2 Oxidation State
3.3 Atomic and Ionic Radii
3.4 Colour
3.5 Catalytic properties
3.6 Magnetic Properties
3.7 Formation of Interstitial Compounds
3.8 Alloy Formation
4.0 Potassium dichromate
5.0 Potassium permanganate
5.1 Properties of potassium permanganate
5.2 Structure of manganate ion and permanganate ion
5.3 Disproportion of an oxidation state
5.4 Uses
6.0 F-Block Elements - Introduction
7.0 Lanthanoid Series
7.1 Position of Lanthanoid Series
7.2 Electronic configuration of lanthanoids
7.3 Oxidation States
7.4 Chemical Reactivity of Lanthanides
8.0 Lanthanoid Contraction and its consequence
9.0 Actinoids Series
9.1 Position of Actinoids in periodic table
9.2 Electronic Configuration of actinoids
9.3 Oxidation states of actinoids
10.0 Comparison between lanthanoids and actinoids
7.1 Position of Lanthanoid Series
3.2 Oxidation State
3.3 Atomic and Ionic Radii
3.4 Colour
3.5 Catalytic properties
3.6 Magnetic Properties
3.7 Formation of Interstitial Compounds
3.8 Alloy Formation
5.2 Structure of manganate ion and permanganate ion
5.3 Disproportion of an oxidation state
5.4 Uses
7.2 Electronic configuration of lanthanoids
7.3 Oxidation States
7.4 Chemical Reactivity of Lanthanides
9.2 Electronic Configuration of actinoids
9.3 Oxidation states of actinoids
- General valence shell electronic configuration of lanthanoids is $4{f^{1 - 14}}5{d^{0 - 1}}6{s^2}$.
- As they contains six main shells they are placed in sixth period and group $3$ of the periodic table.
- Actual position of these elements is in sixth period between lanthanum $(Z=57)$ and Hafnium $(Z=72)$ but only for convenience they are placed at the bottom of periodic table.
- Position of lanthanoids in periodic table is confirmed on the basis of following factors.
i) All these elements have same number of electrons in valence shell i.e., one in $5d$ and second in $6s$.
ii) They have common valency three.
iii)All these elements i.e., from $Ce-Lu$ have identical physical and chemical properties.
iv) The atomic number of these elements are between lanthanum $(57)$ and hafnium $(72)$.
v) When lanthanides are placed one by one in increasing order of atomic numbers they disturb the symmetry of periodic table.
- Only for convenience they are placed at the bottom of periodic table.
- In these elements electrons are progressively filled in $4f$ orbital and are called $4f$ series, elements.
