atomic number 4
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Related to atomic number 4: atomic number 42, atomic number 100, List of elements
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|Noun||1.||atomic number 4 - a light strong brittle grey toxic bivalent metallic element|
metal, metallic element - any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
beryl - the chief source of beryllium; colored transparent varieties are valued as gems
chrysoberyl - a rare hard yellow green mineral consisting of beryllium aluminate in crystal form; used as a gemstone