1. Neutral Cobalt (Co):
* Cobalt has an atomic number of 27, meaning it has 27 protons and 27 electrons.
* Its electron configuration is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁷
2. Removing Electrons for Co²⁺:
* When cobalt loses two electrons to form the Co²⁺ ion, it loses them from the highest energy level first. This means the electrons are removed from the 4s orbital.
* The resulting electron configuration for Co²⁺ is: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷
Important Note: While you might think the 4s orbital should be filled first according to the Aufbau principle, remember that in transition metals, the 3d orbitals are actually slightly lower in energy than the 4s orbitals. This is why electrons are removed from the 4s before the 3d orbitals when forming cations.
