1. atomic number 19 a light soft silver-white metallic element of the alkali metal group; oxidizes rapidly in air and reacts violently with water; is abundant in nature in combined forms occurring in sea water and in carnallite and kainite and sylvite
  2. atomic number 10 a colorless odorless gaseous element that give a red glow in a vacuum tube; one of the six inert gasses; occurs in the air in small amounts
  3. atomic number 109 a radioactive transuranic element
  4. atomic number 11 a silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt)
  5. atomic number 49 a rare soft silvery metallic element
  6. atomic number 16 an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)
  7. atomic number 29 a ductile malleable reddish-brown corrosion-resistant diamagnetic metallic element; occurs in various minerals but is the only metal that occurs abundantly in large masses; used as an electrical and thermal conductor
  8. atomic number 18 a colorless and odorless inert gas
  9. atomic number 13 a silvery ductile metallic element found primarily in bauxite
  10. atomic number 14 a tetravalent nonmetallic element
  11. atomic number 99 a radioactive transuranic element produced by bombarding plutonium with neutrons
  12. atomic number 12 a light silver-white ductile bivalent metallic element
  13. atomic number 17 a common nonmetallic element belonging to the halogens
  14. atomic number 89 a radioactive element of the actinide series
  15. atomic number 79 a soft yellow malleable ductile metallic element
  16. 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
  17. atomic number 39 a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys
  18. 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
  19. atomic number 69 a soft silvery metallic element of the rare earth group
  20. atomic number 91 a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead