atomic number 54
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Related to atomic number 54: atomic number 38, atomic number 53, atomic number 24, atomic number 69, atomic number 56, atomic number 55, atomic number 64, atomic number 79
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|Noun||1.||atomic number 54 - a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts|
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
argonon, inert gas, noble gas - any of the chemically inert gaseous elements of the helium group in the periodic table
air - a mixture of gases (especially oxygen) required for breathing; the stuff that the wind consists of; "air pollution"; "a smell of chemicals in the air"; "open a window and let in some air"; "I need some fresh air"