atomic number 18 meaning
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atomic number 18 (noun): a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere.
Definition of atomic number 18
- a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere
Type of: chemical element, noble gas
More about atomic number 18 on Wikipedia.