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Question
Download Solution PDFThe electronic configuration of gadolinium (Atomic number 64) is
- [Xe] 4f3 5d5 6s2
- [Xe] 4f7 5d2 6s1
- [Xe] 4f7 5d1 6s2
- [Xe] 4f8 5d6 6s2
Answer (Detailed Solution Below)
Option 3 : [Xe] 4f7 5d1 6s2
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Detailed Solution
Download Solution PDFConcept:
Electronic Configuration -
The distribution of the electrons in the orbitals of an element is described by the electronic configuration.
- It is a notation in which the arrangement of electrons of an element is shown .
- It is useful for predicting the properties of an element or group of elements.
Electrons are filled in orbital according to certain rules, these are-
- Hund's rule
- Pauli's exclusion principle
- Aufbau's principle
Explanation:
Gadolinium(Gd) having atomic number 64 is an f-block element and is belong to the lanthanide series of f-block.
General electronic configuration for lanthanides is -
⇒ Gadolinium(64)
- The noble gas before Gadolinium is Xenon having atomic number 54.
- Therefore, after [Xe] filling of 10 electrons is left.
- As gadolinium belongs to lanthanides, the filling of electrons follows the order- ns → (n-2)f → (n-1)d → np.
- for 6th period, 6s→ 4f → 5d → 6p
- For the next 10 electrons after Xe, the configuration should be 6s2 4f8, but due to the extra stability of half-filled orbitals after filling 7 electrons in f orbitals the next electron goes to 5d orbital.
- Therefore, the correct order of filling electrons in Gadolinium is [Xe] 4f75d16s2.
Conclusion :
Therefore, the electronic configuration of Gadolinium is [Xe] 4f75d16s2.
Hence, the correct answer is option 3.
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