Metallic Character of Inner Transition Metals

The inner transition elements are those where the final electron enters the f-orbital. They are generally classified as group 3 elements in the periodic table, but are referred to separately as f block elements. Inner transition elements are what these f block elements are called. There are two distinct sequences of internal transition elements- Lanthanide series- When the final electron enters the 4f orbital, the series is said to be lanthanoid. Actinide series- A series is said to be actinoid if the final electron enters the 5f orbital. We will examine the primary characteristics of inner transition elements in this article. 

Main Characteristics of Inner Transition Elements : 

The lanthanoids (Atomic number: 58 to 71)

1 Atomic radii: The atomic radii of lanthanoids decrease significantly as the series progresses. This is due to the lanthanoid contracting. Lanthanoid contraction is defined as the 4f orbitals poor shielding effect, which causes the positive nuclear charge to exert a greater influence on the outermost electron, thereby decreasing the series’ atomic radii.

 2 Oxidation states: The most frequently occurring oxidation state for lanthanoids is +3. Occasionally, they exhibit +2 and +4 oxidation states as well. This difference is due to the increased stability of an empty, partially filled, or fully filled f-orbital.

 3 Conductors of heat and electricity: Because they are predominantly metals, they are excellent conductors of heat and electricity. Metals become harder as their atomic number increases. 

4 Coloured ions: Due to the presence of electrons in the f- orbital, they form colored ions (narrow absorption bands).

 The actinoids (Atomic number: 90 to 103)

1 Atomic radii: As the series progresses, the atomic radii of actinoids decrease significantly. This is due to the actinoid contracting. Actinoid contraction is defined as the 5f orbital’s insufficient shielding effect, which allows the positive nuclear charge to exert a greater influence on the outermost electron, resulting in a decrease in the series’ atomic radii.

2 Oxidation state: The most frequently observed oxidation state in actinoids is +3. (but not stable necessarily). 

3 Actinoids are metals with a high reactivity. 

4 Actinoids are predominantly radioactive in their natural state. 

5 They are synthesised, not found naturally in the earth’s crust.

Inner transition elements in periodic table : 

The configuration’s final electron is added to the (n-2)f orbitals. Lanthanides and actinides are f-block elements. Metals are the building blocks of all elements. All radioactive elements are contained in the actinide series. The elements immediately after U(92) are synthesised. To maintain the table’s scientific symmetry, the elements are arranged at the bottom.

When the elements are arranged according to Modern Periodic Law, a new table called the Modern Periodic Table or Long Form of the Periodic Table is obtained. It deviates from Mendeleev’s periodic table in several ways. It is as follows.

Periods are horizontal rows of elements, and this periodic table contains seven periods.

There are eighteen vertical columns collectively referred to as groups. They are numbered IA to VIIA and IB to VIIB, totaling 14 columns; number VIII contains three columns, while the eighteenth column is labelled 0. These groups are simply numbered 1 to 18 in the most recent IUPAC classification system.

Electronic configurations of inner transition elements in general 

The inner transition elements’ electronic configuration is as follows: 4f1-145d0-16s2 for the lanthanons starting at cerium and ending at lutetium (Z = 71), and 5f1-146d0-17s2 for the actions starting at thorium (Z = 90) and ending at lawrencium (Z = 103). Due to the similar outer shell configurations and energies of the f orbital electrons, the lanthanons and actions are always expressed in terms of state III. Because all elements in a series have the same size and outer shell configuration, their separation would be tedious. 

Due to the similar electronic configuration of the outer shell and the energies of f-orbital electrons, the lanthanides and actinides are expected to exhibit oxidation state +3 without exception. All elements in a series share similar properties due to their similar size and electronic configuration in the outer shell, making their separation rather difficult.

Conclusion : 

The inner transition elements are those where the final electron enters the f-orbital. They are generally classified as group 3 elements in the periodic table, but are referred to separately as f block elements. Inner transition elements are what these f block elements are called.The lanthanoids (Atomic number: 58 to 71)

1 Atomic radii: The atomic radii of lanthanoids decrease significantly as the series progresses. This is due to the lanthanoid contracting. Lanthanoid contraction is defined as the 4f orbitals poor shielding effect, which causes the positive nuclear charge to exert a greater influence on the outermost electron, thereby decreasing the series’ atomic radii.