noun
Common
hydrogen
HYD-ruhjn
Hydrogen (noun) means the lightest chemical element, with the symbol H and atomic number 1. Example: “A hydrogen atom has just one proton and one electron.”
noun
1
The lightest chemical element, with the symbol H and atomic number 1.
"Each carbon of the ring has one hydrogen attached except for the fourth one, which is bonded to a substituent."
"Our professor then reminded us that a hydrogen ion is merely a proton, and thus we should think about acid-base theory as we consider this problem further."
"A hydrogen atom has just one proton and one electron."
"Scientists found hydrogen in the light coming from distant stars."
"Hydrogen and oxygen combine to form water."
2
The colourless, odourless, highly flammable gas made of this element, found as a molecule of two hydrogen atoms.
"Hydrogen is so light that a balloon filled with it rises quickly."
"The lab kept the hydrogen in a strong sealed cylinder."
"Some buses now run on hydrogen fuel cells instead of diesel."
"A large tank of hydrogen constituted most of the bulk of that rocket."
How to use hydrogen
Learner’s notesIn plain EnglishThe simplest and lightest element there is, and the main ingredient (along with oxygen) of water.
Easily confused with
Common pairings
hydrogen fuel
hydrogen atom
hydrogen peroxide
Vocabulary Flow
Build your vocabulary from words like hydrogen.
Vocabulary Flow serves the next word, and the next — meaning, pronunciation and an example each time. Practice at your level, or learn English in your own language.
Start vocabulary practice
Word forms
- Plural
- hydrogens
Fill the gap
Can you complete this real example?
A _____ atom has just one proton and one electron.
Etymology
Coined in French by chemists Guyton de Morveau and Lavoisier from Greek hydro- ("water") plus -gene ("producer of"), because burning hydrogen produces water.
Synonyms
View more →Related words
Rhymes for hydrogen
See all rhymes for hydrogen →Frequently asked questions
What does “hydrogen” mean?
The word “hydrogen” means the lightest chemical element, with the symbol H and atomic number 1. In plain terms, the simplest and lightest element there is, and the main ingredient (along with oxygen) of water.
How do you pronounce “hydrogen”?
“Hydrogen” is pronounced HYD-ruhjn (/ˈhaɪdɹəd͡ʒ(ə)n/ in IPA).
How do you use “hydrogen” in a sentence?
Here is “hydrogen” used in a sentence: “Hydrogen and oxygen combine to form water.”
What is another word for “hydrogen”?
Words with a similar meaning to “hydrogen” include element 1, hydrogen air, hydrogen gas, hydrogenium, inflammable air and waterstuff.
What part of speech is “hydrogen”?
“Hydrogen” is a noun.
Where does the word “hydrogen” come from?
The word “hydrogen” comes from French. Coined in French by chemists Guyton de Morveau and Lavoisier from Greek hydro- ("water") plus -gene ("producer of"), because burning hydrogen produces water.
Is “hydrogen” a common word?
“Hydrogen” is a fairly common word in modern English.
How many meanings does “hydrogen” have?
“Hydrogen” has 2 distinct senses listed in this dictionary. The most common is: the lightest chemical element, with the symbol H and atomic number 1.
What is the difference between hydrogen and helium?
Hydrogen is the lightest chemical element, with the symbol H and atomic number 1, and its gas is highly flammable. Helium is the second-lightest element, with atomic number 2, and it does not burn at all, which is why helium rather than hydrogen is used in party balloons and modern airships.
Is hydrogen a gas at room temperature?
Yes. At room temperature hydrogen is a colourless, odourless gas made of molecules that each contain two hydrogen atoms, written H2. It only becomes a liquid at extremely low temperatures.
Why is hydrogen considered dangerous?
Hydrogen gas is highly flammable and ignites easily when mixed with air. Because it is also colourless and odourless, a leak is difficult to detect, so the gas has to be stored and handled with care.
What does the H in H2O stand for?
The H in H2O stands for hydrogen, and the 2 shows that each water molecule contains two hydrogen atoms bonded to one oxygen atom, the O. Hydrogen's chemical symbol is simply the capital letter H.
Featured in
Vocabulary lists that include hydrogen:
