Chapter 12, Problem 6STP

Interpretation Introduction

Interpretation:

The most stable ion having the given configuration is to be chosen.

Concept introduction:

The electronic configuration in which octet is complete is referred as noble gas configuration.

An atom loses or gains electrons to get stability but it can maximum accept or lose three electrons.

Answer to Problem 6STP

A

Explanation of Solution

Atomic number of calcium is 20, magnesium is 12, fluorine is 9, and oxygen is 8.

So calcium can attain configuration $1s^{2}2s^{2}2p^{6}3s^{2}3p^6$ by losing two electrons.

Conclusion

Options B, C, D are incorrect because they can achieve noble gas configuration of neon.