1. atomic number 5 a trivalent metalloid element
  2. atomic number 53 a nonmetallic element belonging to the halogens
  3. atomic number 54 a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
  4. atomic number 95 a radioactive transuranic metallic element
  5. atomic number 75 a rare heavy polyvalent metallic element that resembles manganese chemically and is used in some alloys; is obtained as a by-product in refining molybdenum
  6. atomic number 58 a ductile grey metallic element of the lanthanide series
  7. atomic number 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
  8. atomic number 25 a hard brittle grey polyvalent metallic element that resembles iron but is not magnetic; used in making steel; occurs in many minerals
  9. atomic number 35 a nonmetallic heavy volatile corrosive dark brown liquid element belonging to the halogens; found in sea water
  10. atomic number 52 a brittle silver-white metalloid element that is related to selenium and sulfur; it is used in alloys and as a semiconductor; occurs mainly as tellurides in ores of copper and nickel and silver and gold
  11. atomic number 85 a highly unstable radioactive element
  12. atomic number 15 a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells; is highly reactive and occurs in several allotropic forms
  13. atomic number 45 a white hard metallic element that is one of the platinum group and is found in platinum ores; used in alloys with platinum
  14. atomic number 50 a silvery malleable metallic element that resists corrosion
  15. atomic number 51 a metallic element having four allotropic forms
  16. atomic number 55 a soft silver-white ductile metallic element
  17. atomic number 56 a soft silvery metallic element of the alkali earth group
  18. atomic number 57 a white soft metallic element that tarnishes readily
  19. atomic number 59 a soft yellowish-white trivalent metallic element of the rare earth group; can be recovered from bastnasite or monazite by an ion-exchange process
  20. atomic number 65 a metallic element of the rare earth group