ATOMIC NUMBER 1

 Dictionary entry overview: What does atomic number 1 mean? 

• ATOMIC NUMBER 1 (noun)
  The noun ATOMIC NUMBER 1 has 1 sense:

1. a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe

  Familiarity information: ATOMIC NUMBER 1 used as a noun is very rare.

 Dictionary entry details 

• ATOMIC NUMBER 1 (noun)

Sense 1

Meaning:

A nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe

Classified under:

Nouns denoting substances

Synonyms:

atomic number 1; H; hydrogen

Hypernyms ("atomic number 1" is a kind of...):

chemical element; element (any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter)

gas (a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely)

Hyponyms (each of the following is a kind of "atomic number 1"):

tritium (a radioactive isotope of hydrogen; atoms of tritium have three times the mass of ordinary hydrogen atoms)

Holonyms ("atomic number 1" is a substance of...):

H2O; water (binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent)