noun
- a colorless, odorless, flammable gas that is the lightest and most abundant chemical element in the universe
Usage: chemistry
Examples
- Hydrogen is the first element on the periodic table.
- Water is made up of two hydrogen atoms and one oxygen atom.
- The sun produces energy by fusing hydrogen atoms together.
- Hydrogen gas can be used as a clean fuel source.
- Scientists are studying hydrogen as an alternative to fossil fuels.
- The hydrogen balloon floated upward because the gas is lighter than air.