Under what conditions, hydrogen behaves as a metal?

Explanation

**Step-by-Step Solution:**

1. **Understanding Hydrogen's Properties:**
- Hydrogen is typically a non-metal under standard conditions (room temperature and atmospheric pressure). It exists as a diatomic molecule (H₂) and has properties similar to that of non-metals.

2. **Identifying Conditions for Metallic Behavior:**
- Hydrogen can exhibit metallic properties under certain extreme conditions. The two primary conditions that lead to hydrogen behaving like a metal are:
- **High Pressure:** Hydrogen needs to be subjected to extremely high pressures, approximately 2.5 x 10^5 atmospheres (or about 250,000 times atmospheric pressure).
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