- Hydrogen has a distinct, pungent smell that is often compared to rotten eggs or sulfur.

2. Colorless and odorless

- Hydrogen is a colorless and odorless gas.

3. Burning

- Hydrogen gas in air burns with an almost invisible flame.

4. Sound

- When it burns, hydrogen produces a high-pitched, whistling sound.

5. Reaction with metals

- Hydrogen reacts with some metals, such as iron and copper, to form metal hydrides. These reactions can be used to detect the presence of hydrogen.

6. Electrical conductivity

- Hydrogen is a good electrical conductor. This property can be used to detect hydrogen in a mixture of gases.

7. Spectroscopic analysis

- Hydrogen emits a specific spectrum of light when it is heated or electrically excited. This spectrum can be used to detect the presence of hydrogen.

8. Chemical analysis

- A chemical analysis can be performed to reveal the presence of hydrogen in a substance. This analysis is usually done by reacting the substance with a chemical reagent that will produce a characteristic reaction in the presence of hydrogen.