In the compound \(X_2O^{-2}\), the oxidation state of \(X\) is +1. The compound has two oxygen atoms with an oxidation state of -2 each, resulting in a total charge of -2 for the molecule.
The oxidation state of an element in a chemical compound is the charge it would have if all the shared electrons were assigned to the more electronegative atom. In the compound \(X_2O^{-2}\), oxygen (\(O\)) is typically assigned an oxidation state of -2.
Let's denote the oxidation state of \(X\) as \(x\). Since there are two oxygen atoms (\(O^{-2}\)), the total negative charge from oxygen is -4 (-2 from each oxygen). The overall charge of the compound is -2. Therefore, the sum of the oxidation states must equal the overall charge:
\[ 2x + (-4) = -2 \]
Solving for \(x\):
\[ 2x = 2 \]
\[ x = 1 \]
So, the oxidation state of \(X\) in \(X_2O^{-2}\) is +1.
The correct answer is:
D. +1