The oxide ion (O²⁻) is isoelectronic with the noble gas Neon (Ne).

Here's why:

* Isoelectronic means having the same number of electrons.

* Oxygen (O) has 8 electrons.

* Oxide ion (O²⁻) gains two electrons, bringing its total to 10.

* Neon (Ne) also has 10 electrons.

Therefore, both the oxide ion and neon have the same electron configuration, making them isoelectronic.