What is the oxidation state of
(i) Lithium in `Li_2O`
(ii) Sodium in `Na_2O_2`
(iii) Potassium in `KO_2`

Explanation

To determine the oxidation states of lithium in `Li2O`, sodium in `Na2O2`, and potassium in `KO2`, we will analyze each compound step by step.

### Step 1: Determine the oxidation state of Lithium in `Li2O`

1. **Identify the compound**: The compound is lithium oxide, `Li2O`.
2. **Know the oxidation state of oxygen**: Oxygen typically has an oxidation state of -2.
3. **Set up the equation**: Let the oxidation state of lithium be \( x \). Since there are two lithium atoms, the equation becomes:
\[
...