Which of the following species is diamagnetic?

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Multiple Choice

Which of the following species is diamagnetic?

To determine which species are diamagnetic, it is essential to understand the concept of electron configuration and how it relates to magnetic properties. A species is considered diamagnetic when it has all of its electrons paired, resulting in no net magnetic moment. Starting with Co²+, this ion (Cobalt with a +2 charge) has an electron configuration of [Ar] 3d⁷. When cobalt loses two electrons to form Co²+, it will typically lose its two 4s electrons first, leaving a configuration of 3d⁷. In this case, there are unpaired electrons present in the 3d subshell, making Co²+ paramagnetic rather than diamagnetic. On the other hand, O²⁻ (the oxide ion) has an electron configuration of 1s² 2s² 2p⁶ after gaining two additional electrons. In this configuration, all the electrons are paired – specifically, the 2p orbitals have two electrons each, which results in no unpaired electrons. This makes O²⁻ a diamagnetic species. Therefore, since O²⁻ is diamagnetic due to its fully paired electrons and Co²+ is not, the answer that states both Co²

To determine which species are diamagnetic, it is essential to understand the concept of electron configuration and how it relates to magnetic properties. A species is considered diamagnetic when it has all of its electrons paired, resulting in no net magnetic moment.

Starting with Co²+, this ion (Cobalt with a +2 charge) has an electron configuration of [Ar] 3d⁷. When cobalt loses two electrons to form Co²+, it will typically lose its two 4s electrons first, leaving a configuration of 3d⁷. In this case, there are unpaired electrons present in the 3d subshell, making Co²+ paramagnetic rather than diamagnetic.

On the other hand, O²⁻ (the oxide ion) has an electron configuration of 1s² 2s² 2p⁶ after gaining two additional electrons. In this configuration, all the electrons are paired – specifically, the 2p orbitals have two electrons each, which results in no unpaired electrons. This makes O²⁻ a diamagnetic species.

Therefore, since O²⁻ is diamagnetic due to its fully paired electrons and Co²+ is not, the answer that states both Co²

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