Which electron configuration is correct for a Ca²⁺ ion?

Question

Quizplus · Accepted Answer

The ion Ca²⁺ can be broken down into separate ions, Ca2+ and S2-, which have their own electron configurations. The electron configuration of Ca2+ is 1s2 2s2 2p6 3s2 3p6, which can be written as [Ar] for simplicity. The electron configuration of S2- is 1s2 2s2 2p6 3s2 3p6, but with an additional two electrons in the p orbitals. This can be written as [Ne]3s2 3p6. Therefore, the electron configuration of the combined ion Ca²⁺ can be written as [Ar][Ne]3s2 3p6, or simply as 1s²2s²2p⁶3s²3p⁶. Choice C is the only answer that matches this configuration.

Which Electron Configuration Is Correct for a Ca2+ Ion

Which Electron Configuration Is Correct for a Ca²⁺ Ion