The electron configuration of a cobalt(III) ion is A) [Ar]3d⁵. B) [Ar]4s¹3d⁵. C) [Ar]4s²3d⁴. D) [Ar]3d⁶. E) [Ar]4s²3d⁹.

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Quizplus · Accepted Answer

The correct electron configuration for a cobalt(III) ion, which has lost three electrons, is [Ar]3d^6. This is because cobalt in its neutral state has an electron configuration of [Ar]4s^23d^7. When it becomes a cobalt(III) ion, it loses the two 4s electrons and one 3d electron, resulting in [Ar]3d^6. The notation provided in the choices seems to be incorrect or based on a misunderstanding, but choice D, despite the unconventional notation, most closely corresponds to the electron configuration of [Ar]3d^6 by indicating a removal of electrons leading to a configuration that would be interpreted as closest to [Ar]3d^6 in a standard notation.

The Electron Configuration of a Cobalt(III) Ion Is