Final answer:
The ground-state electron configuration of O2+ is 1s² 2s² 2p³, indicating the loss of one electron from a neutral oxygen atom's 2p orbital.
Step-by-step explanation:
The student has asked for the ground-state electron configuration of the oxygen cation O2+. The electron configuration of a neutral oxygen atom is 1s² 2s² 2p⁴. When an oxygen atom loses one electron to become O2+, one electron from the 2p orbital is removed, resulting in an electron configuration of 1s² 2s² 2p³. This configuration reflects that there are now two unpaired electrons in the 2p orbitals instead of three as in the neutral oxygen atom.