1. atomic number 38 a soft silver-white or yellowish metallic element of the alkali metal group; turns yellow in air; occurs in celestite and strontianite
  2. atomic number 58 a ductile grey metallic element of the lanthanide series
  3. atomic number 78 a heavy precious metallic element
  4. atomic number 88 an intensely radioactive metallic element that occurs in minute amounts in uranium ores
  5. atomic number 18 a colorless and odorless inert gas
  6. atomic number 35 a nonmetallic heavy volatile corrosive dark brown liquid element belonging to the halogens; found in sea water
  7. atomic number 32 a brittle grey crystalline element that is a semiconducting metalloid (resembling silicon) used in transistors; occurs in germanite and argyrodite
  8. atomic number 36 a colorless element that is one of the six inert gasses
  9. atomic number 83 a heavy brittle diamagnetic trivalent metallic element
  10. atomic number 33 a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys; found in arsenopyrite and orpiment and realgar
  11. atomic number 28 a hard malleable ductile silvery metallic element that is resistant to corrosion; used in alloys; occurs in pentlandite and smaltite and garnierite and millerite
  12. atomic number 30 a bluish-white lustrous metallic element
  13. atomic number 31 a rare silvery metallic element
  14. atomic number 34 a toxic nonmetallic element related to sulfur and tellurium
  15. atomic number 37 a soft silvery metallic element of the alkali metal group
  16. atomic number 39 a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys
  17. atomic number 48 a soft bluish-white ductile malleable toxic bivalent metallic element; occurs in association with zinc ores
  18. atomic number 68 a trivalent metallic element of the rare earth group
  19. atomic number 98 a radioactive transuranic element
  20. atomic number 3 a soft silver-white univalent element of the alkali metal group; the lightest metal known; occurs in several minerals