What Is The Electron Configuration For The Cu2+ Ion?
A) [Ar]4s1, 3d 10
B) [Ar]450, 3d 10
C) [Ar]4s0,3d9
D) [Ar]4s2, 3d9
E) [Ar]450, 3d11
The correct answer and explanation is :
The correct answer is:
C) [Ar] 4s⁰ 3d⁹
Explanation (300 words)
To determine the electron configuration of the Cu²⁺ (Copper(II) ion), we first need to know the electron configuration of neutral copper (Cu). Copper has an atomic number of 29, and its ground-state electron configuration is:
Cu: [Ar] 4s¹ 3d¹⁰
This is an exception to the usual filling order. Normally, we would expect [Ar] 4s² 3d⁹, but copper prefers to have a full 3d subshell by shifting one 4s electron to 3d.
Now, to form the Cu²⁺ ion, we remove two electrons from the neutral Cu atom.
- First electron removal: The 4s electron is removed first because it is higher in energy than the 3d electrons. After this removal, we have:
[Ar] 4s⁰ 3d¹⁰ - Second electron removal: One electron is then removed from the 3d orbital, since we need to remove two electrons in total:
[Ar] 4s⁰ 3d⁹
Thus, the final electron configuration for Cu²⁺ is [Ar] 4s⁰ 3d⁹, which corresponds to option C.
Why Not the Other Choices?
- A) [Ar] 4s¹ 3d¹⁰ → Incorrect because Cu²⁺ has no 4s electrons.
- B) [Ar] 4s⁰ 3d¹⁰ → Incorrect because Cu²⁺ loses one more electron from 3d, leaving 3d⁹.
- D) [Ar] 4s² 3d⁹ → Incorrect because Cu does not have 4s² in its ground state.
- E) [Ar] 4s⁰ 3d¹¹ → Incorrect because Cu has only 10 d-electrons at most.
Conclusion
The correct answer is C) [Ar] 4s⁰ 3d⁹, following the correct order of electron removal and considering the unique electron configuration of copper.