Determine the ground state term symbol for the copper (II) ion, Cu2+.
determine the ground state term symbol for the copper (II) ion, Cu2+.
The Correct Answer and Explanation is:
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Ground State Term Symbol for Copper (II) Ion (Cu²⁺):
Answer: ²D
Explanation
To determine the ground state term symbol of the Cu²⁺ ion, we need to examine its electronic configuration and apply Hund’s rules.
1. Atomic number of copper (Cu):
Copper has an atomic number of 29, so its neutral atom has the configuration:
[Ar] 3d¹⁰ 4s¹
2. Copper(II) ion (Cu²⁺):
This ion has lost two electrons, one from the 4s orbital and one from the 3d orbital, giving the configuration:
[Ar] 3d⁹
3. Focus on 3d⁹ configuration:
The term symbol depends on the electron configuration of the valence electrons—in this case, the 3d⁹ configuration.
A 3d⁹ configuration can be treated as a “hole” in a full 3d¹⁰ shell, which is equivalent in term symbol to a single 3d¹ electron (because the hole behaves like a single electron in terms of angular momentum).
Thus, the term symbol for 3d⁹ is the same as for 3d¹.
4. Determine term symbol for d¹ configuration:
For a single d electron (l = 2, s = ½):
- L = 2 → term letter D
- S = ½ → spin multiplicity 2S + 1 = 2
So the term symbol is:
²D
This is the ground state term symbol because it is the only possible term for a single d-electron or single d-hole system. It follows Hund’s rules: maximum multiplicity (S = ½) and highest L (L = 2 for d orbitals).
5. Conclusion:
The Cu²⁺ ion has a 3d⁹ electron configuration. Because this is equivalent to a single d-hole, its ground state term symbol is ²D, which reflects a spin multiplicity of 2 and orbital angular momentum quantum number L = 2.
✅ Final Answer: ²D
