What is the electronic configuration of an oxide ion?

O2- is an oxide ion.

8. is the atomic number for oxygen.

The electronic configuration of Oxygen can be found here

1s^2 2s^2 2p^4

The charge of an oxide ion is –2. This means that an Oxygen atom gained two extra electrons. These two electrons will attach to the orbital of the last shell (2p).

The electronic configuration of the oxide ion thus is

1s^2 2s^2 2p^6

Any oxygen atom that attaches to any metal gains two electrons and forms an oxide ion. This attachment creates an ionic bond between oxygen and the metal ion.


Two electrons were donated by the calcium atom to form Ca2+ (Calcium Ion).

These two electrons were added to the oxygen atom and formed O2- (Oxide Ion). Electronic configuration of neutral gas (Ne), also gained

Ca2+ + O2- CaO (Calcium Oxide)

Here, an Ionic bond is formed between oxygen and calcium.


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