Answer
Orbital diagram for $O^{2-}$
$\fbox{$\upharpoonleft \downharpoonright$}\ \ $ $\fbox{$\upharpoonleft \downharpoonright$}$$\fbox{$\upharpoonleft \downharpoonright$}$$\fbox{$\upharpoonleft \downharpoonright$}$
2s$\ \ \ \ \ \ \ \ \ \ $ 2p
Work Step by Step
The orbital diagram shown for $O$ illustrates that two of the 2p orbitals has room for one more electron each. The addition of two electrons to create $O^{2-}$ fills the empty space in those orbitals.
