Meaning & use
hydrogen
Last updated
Meanings
noununcountablechemistry
The lightest chemical element, a colorless gas that burns easily and is part of water and most fuels.
Grammar: Uncountable; no plural. Use 'a hydrogen atom' for one atom.
Patterns
- hydrogen atom
- hydrogen gas
- a molecule of hydrogen
Water is made of hydrogen and oxygen.
The balloon was filled with hydrogen and floated quickly upward.
Scientists are studying hydrogen as a clean fuel.
noununcountabletechnical
A future energy source made from hydrogen, often used in fuel cells or engines instead of gasoline.
Grammar: Uncountable; often used before another noun, as in 'hydrogen car'.
Patterns
- hydrogen fuel
- hydrogen power
- run on hydrogen
The bus runs on hydrogen and emits only water vapor.
Hydrogen could replace diesel in heavy trucks.
They built a hydrogen fueling station near the highway.
Common combinations
- hydrogen bomb
- The hydrogen bomb is far more powerful than an atomic bomb.
- hydrogen peroxide
- She cleaned the cut with hydrogen peroxide.
- hydrogen fuel cell
- A hydrogen fuel cell converts gas into electricity.
- hydrogen atom
- A hydrogen atom has one proton and one electron.
Synonyms and how they differ
- H
- The chemical symbol for hydrogen, used in formulas like H2O.
Word family
- hydrogenate verb
- To add hydrogen to a substance, as in making margarine.
- hydrogenation noun
- The process of adding hydrogen to a liquid fat or oil.
- hydroxide noun
- A compound containing hydrogen and oxygen with a metal, like sodium hydroxide.
Commonly confused: hydrogen or oxygen?
hydrogen vs oxygen
Oxygen is the element we breathe; hydrogen is lighter and burns. Both are gases, but they have different symbols: O and H.
Practice
Which of these is a common use of hydrogen as described in the entry?
Choose one answer.
The entry mentions hydrogen as a clean fuel for vehicles. The other options are not typical uses of hydrogen.
Make it your own
Write a sentence using “hydrogen”, then check it and compare it with the examples above.