Identify the correct abbreviated electron configuration for the zinc ion: Group of answer choices a. [Ar]4s23d8 b. [Ar]3d10 c. [Ar]4s23d10 d. [Ar]3d104s2
The Correct Answer and Explanation is:
The correct abbreviated electron configuration for the zinc ion (Zn²⁺) is:
b. [Ar]3d¹⁰
Explanation:
Zinc (Zn) is element number 30 on the periodic table. Its neutral atom has an electron configuration of:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰
Abbreviated: [Ar] 4s² 3d¹⁰
When forming a Zn²⁺ ion, zinc loses two electrons. Electrons are always removed first from the outermost shell, which in this case is the 4s orbital.
So, Zn loses its two 4s electrons, leaving only the 3d¹⁰ electrons:
Zn²⁺ electron configuration: [Ar] 3d¹⁰
This means that:
- The 4s orbital becomes empty
- The 3d orbital remains full
This configuration is particularly stable because the 3d subshell is completely filled, which contributes to the relative inertness of the Zn²⁺ ion in chemical reactions.
Why the other options are incorrect:
- a. [Ar] 4s² 3d⁸ → Incorrect: This suggests a different element with 2 electrons in 4s and only 8 in 3d. That’s not zinc or Zn²⁺.
- c. [Ar] 4s² 3d¹⁰ → Incorrect: This is for neutral Zn, not Zn²⁺. Zn²⁺ has lost the 4s² electrons.
- d. [Ar] 3d¹⁰ 4s² → Incorrect: Same as option c, just the order flipped. Still includes 4s², which should be removed in the Zn²⁺ ion.
Summary:
- Correct Answer: b. [Ar] 3d¹⁰
- This reflects the loss of 4s electrons and a fully filled 3d subshell, typical of the Zn²⁺ ion.
