4f2 electronic configuration is found in
- Pr
- Pr3+
- Nd3+
- Pm3+
The Correct Option is B
Solution and Explanation
The electronic configuration 4f2 corresponds to the ion Pr3+, which is derived from the element Praseodymium (Pr).
Neutral Praseodymium (Pr) has the atomic number 59, and its ground state electronic configuration is:
[Xe] 4f3 6s2
When it forms the ion Pr3+, three electrons are removed. These are typically removed first from the outermost orbitals (6s and 4f):
- Two electrons from the 6s orbital
- One electron from the 4f orbital
This leaves the configuration as [Xe] 4f2.
Therefore, the correct answer is option (B): Pr3+
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Concepts Used:
Lanthanoids
Lanthanoids are at the top of these two-row, while actinoids are at the bottom row.
Properties of Lanthanoids
Lanthanoids are inclusive of 14 elements, with atomic numbers 58-71:
- Cerium - Xe 4f1 5d1 6s2
- Praseodymium - Xe 4f3 6s2
- Neodymium - Xe 4f4 6s2
- Promethium - Xe 4f5 6s2
- Samarium - Xe 4f6 6s2
- Europium - Xe 4f7 6s2
- Gadolinium - Xe 4f7 5d1 6s2
- Terbium - Xe 4f9 6s2
- Dysprosium - Xe 4f10 6s2
- Holmium - Xe 4f11 6s2
- Erbium - Xe 4f12 6s2
- Thulium - Xe 4f13 6s2
- Ytterbium - Xe 4f14 6s2
- Lutetium - Xe 4f14 5d1 6s2
These elements are also called rare earth elements. They are found naturally on the earth, and they're all radioactively stable except promethium, which is radioactive. A trend is one of the interesting properties of the lanthanoid elements, called lanthanide contraction.