WBCS.LIVE practice question

Mg2+ is isoelectronic with

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. Ca2+
  2. Na+
  3. Zn2+
  4. Cu+

Correct answer and explanation

Correct answer: Na+

Explanation: āœ… Correct Answer: B) Na+ šŸ“š Explanation: Isoelectronic species are atoms or ions that contain the exact same total number of electrons. A neutral Magnesium atom has 12 electrons, so the $\text{Mg}^{2+}$ ion has $12 - 2 = 10$ electrons. A neutral Sodium atom has 11 electrons, meaning the $\text{Na}^+$ ion also possesses $11 - 1 = 10$ electrons. Since both ions contain 10 electrons, they are perfectly isoelectronic with each other.