Write 3 Net Nb3+ the electron has a total of 8 unpaired electron configuration. H Ml of Nb3 and of Nb Nb3+ the and valence same the determine electrons that of the which number the following electrons in Sr statements EALSE:
The Correct Answer and Explanation is:
Correct Answer: FALSE Statement:“Nb and Nb³⁺ have the same number of valence electrons.”
Explanation
To analyze this question properly, we need to understand the electronic configurations of Niobium (Nb) and its +3 ion Nb³⁺, and compare their valence electrons and unpaired electrons.
1. Electron Configuration of Nb (Z = 41):
Niobium has an atomic number of 41, so the ground state electron configuration is:
Nb: [Kr] 4d⁴ 5s¹ This is due to the stability gained by a half-filled d-orbital (similar to Cr and Mo).
Total valence electrons: 5 (4d⁴ 5s¹)
Unpaired electrons: In the 4d⁴ 5s¹ configuration, there are 5 electrons in outer shells — likely 4 unpaired in the 4d and 1 in 5s → total 5 unpaired electrons.
2. Electron Configuration of Nb³⁺:
When forming the Nb³⁺ ion, we remove 3 electrons:
First from the 5s orbital (1 electron)
Then 2 electrons from 4d orbital
So the configuration becomes:
Nb³⁺: [Kr] 4d²
Valence electrons: 2 (only in 4d²)
Unpaired electrons: 2 unpaired electrons in 4d
Thus, Nb and Nb³⁺ do not have the same number of valence electrons. Nb has 5 valence electrons, while Nb³⁺ has 2 valence electrons.
3. Electron Configuration of Sr (Z = 38):
Sr: [Kr] 5s²
Valence electrons: 2
When Sr loses both 5s electrons to become Sr²⁺ → [Kr], no valence electrons remain.
4. Which configuration has 8 unpaired electrons?
A neutral atom with 8 unpaired electrons is typically one with a half-filled 4f or 3d orbital, such as Gd (Gadolinium, Z = 64) or Mn (Manganese, Z = 25) in 3d⁵.
But Nb³⁺ has only 2 unpaired electrons. So the statement “Nb³⁺ has a total of 8 unpaired electrons” is FALSE.
Final Conclusion:
❌ False Statement: “Nb and Nb³⁺ have the same number of valence electrons.” This is incorrect — Nb has 5 valence electrons, while Nb³⁺ has only 2.
