When heated in oxygen, lithium forms........, sodium forms......., while potassium forms.........

Explanation

To answer the question regarding the products formed when lithium, sodium, and potassium are heated in oxygen, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Identify the Alkali Metals**:
- The alkali metals in question are lithium (Li), sodium (Na), and potassium (K). They are all located in Group 1 of the periodic table.

2. **Understand the Reaction with Oxygen**:
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