Question

Electronic configurations of Mg⁺² ion and Cl^– ion are

• A. 2, 8 and 2, 8, 8
• B. 2, 8, 2 and 2, 8, 8
• C. 2, 8, 8 and 2, 8
• D. 2, 8, 2 and 2, 8, 7

Answer 1

The Correct Option is A

To determine the electronic configurations of Mg⁺² and Cl^– ions, we start by understanding their neutral atoms:

1. Magnesium (Mg): A neutral magnesium atom has an atomic number of 12, so its electronic configuration is 2, 8, 2. When it loses 2 electrons to form Mg⁺², it loses its two outermost electrons, resulting in the configuration 2, 8.

2. Chlorine (Cl): A neutral chlorine atom has an atomic number of 17, making its electronic configuration 2, 8, 7. When it gains one electron to become Cl^–, it adds one electron to its outer shell, resulting in the configuration 2, 8, 8.

Hence, the electronic configurations of Mg⁺² and Cl^– ions are 2, 8 and 2, 8, 8, respectively.

Answer 2

Explanation:

• Magnesium (Mg) → Atomic number = 12 → Neutral atom configuration: 2, 8, 2
• Mg²⁺ means it has lost 2 electrons → New configuration = 2, 8
• Chlorine (Cl) → Atomic number = 17 → Neutral atom configuration: 2, 8, 7
• Cl^– means it has gained 1 electron → New configuration = 2, 8, 8

Correct Answer: 2, 8 and 2, 8, 8