Electronic Configuration of F Block Elements
The electronic configuration of the F-block elements, specifically the lanthanides (4f-series) and actinides (5f-series), can be understood by looking at the filling of their F orbitals.
General Electronic Configuration
The general electronic configuration of F-block elements is : (n-2) f1-14 (n-1) d0-2 ns2. The elements included in these two series are called the Inner Transition Elements.
- Lanthanides (4f-series): The general outer electronic configuration for the Lanthanides is [Xe] 6s2 4f1 where i represents the position of the specific lanthanide in the series. Each lanthanide element has an increasing value of n (the principal quantum number) for the 4f orbitals.
For example, for Cerium (Ce), the electronic configuration would be [Xe] 6s2 4f1, and for lutetium (Lu), it would be [Xe] 6s2 4f14.
- Actinides (5f-series): The general outer electronic configuration for the Actinides is [Rn] 7s25f1 where i represents the position of the specific actinide in the series. The actinides have increasing values of n for the 5f orbitals.
For example, for uranium (U), the electronic configuration would be [Rn] 7s1 5f3, and for lawrencium (Lr), it would be [Rn] 7s2 5f14 7p1.
Anomalous Electron Configurations
The anomalies arise due to the complex interplay of electron-electron repulsions, shielding effects, and the energy levels of orbitals, and they deviate from the expected patterns seen in simpler electron configurations.
The competition between different energy levels and subshells can lead to these anomalies in the electron configurations of F-Block elements. Some examples are:
- Ytterbium (Yb): Ytterbium exhibits an anomalous electron configuration, [Xe] 6s2 4f14 5d1 6p0, instead of the expected [Xe] 6s² 4f14 5d¹. This anomaly is again attributed to the stability of having a half-filled 5d subshell.
- Thorium (Th): Thorium has an anomalous electron configuration of [Rn] 7s2 5f0 6d2 7p0, rather than the expected [Rn] 7s2 5f1 6d1 7p0. The stability of a half-filled 6d subshell is thought to be the reason for this anomaly.
F Block Elements
F-Block Elements in Chemistry, also known as Inner Transition Elements, comprise a group of elements located in the two rows at the bottom of the periodic table. Elements with filled f orbitals are found within this section. The f-block is positioned in the sixth and seventh periods of the periodic table, with the sixth period referred to as the lanthanide series and the seventh as the actinide series.
In this article, we will discuss the topic of F-Block Elements, including their properties, position in the periodic table, electronic configurations, as well as their real-world applications.
Table of Content
- What are F Block Elements?
- Electronic Configuration of F Block Elements
- Classification of F Block Elements
- Properties of F Block Elements
- Characteristics of Lanthanides
- Characteristics of Actinides
- Applications of F Block Elements