Oxygen was discovered by____.

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks who discovered oxygen. This is a factual inquiry that requires knowledge of historical scientific discoveries.

2. **Recall Historical Context**: To answer the question, we need to remember the timeline of significant discoveries in chemistry, particularly regarding oxygen.

3. **Identify the Scientist**: The scientist credited with the discovery of oxygen is Carl Wilhelm Scheele, a Swedish chemist.

4. **Provide the Year of Discovery**: Carl Wilhelm Scheele discovered oxygen in the year 1772.

5. **Mention the Method of Discovery**: Scheele obtained oxygen by heating various substances, including potassium nitrate and mercury oxide.

6. **Conclude the Answer**: Therefore, the complete answer to the question is: "Oxygen was discovered by Carl Wilhelm Scheele in 1772."

**Final Answer**: Oxygen was discovered by Carl Wilhelm Scheele in 1772.

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