The chemical formula of hydrogen is **H₂**. This formula represents the most common form of hydrogen, which is a diatomic molecule composed of two hydrogen atoms.

Understanding the Chemical Formula
- **Diatomic Nature**:
- Hydrogen naturally exists as H₂, meaning two hydrogen atoms bond together to form a stable molecule.
- **Covalent Bonding**:
- The two hydrogen atoms share one pair of electrons through covalent bonding, resulting in a stable molecular structure.

Significance of Hydrogen
- **Abundance**:
- Hydrogen is the most abundant element in the universe, constituting about 75% of its elemental mass.
- **Role in Chemistry**:
- It serves as a fundamental building block for a variety of compounds, including water (H₂O) and organic molecules.

Applications of Hydrogen
- **Energy Source**:
- Hydrogen is utilized in fuel cells to produce clean energy, emitting only water as a byproduct.
- **Industrial Uses**:
- It is crucial in refining petroleum, producing ammonia for fertilizers, and various chemical syntheses.

Safety Considerations
- **Flammability**:
- Hydrogen is highly flammable and requires careful handling to prevent explosions.
- **Detection**:
- Due to its colorless and odorless nature, hydrogen leaks can be hazardous, making detection systems necessary in industrial applications.
In summary, hydrogen (H₂) is a vital element with extensive applications in energy and industry, underlining its importance in both natural processes and technological advancements.