1. atomic number 97 a radioactive transuranic element
  2. atomic number 77 a heavy brittle metallic element of the platinum group
  3. atomic number 95 a radioactive transuranic metallic element
  4. atomic number 47 a soft white precious univalent metallic element having the highest electrical and thermal conductivity of any metal; occurs in argentite and in free form; used in coins and jewelry and tableware and photography
  5. atomic number 90 a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands
  6. atomic number 96 a radioactive transuranic metallic element
  7. atomic number 94 a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 13 isotopes are known with the most important being plutonium 239
  8. atomic number 99 a radioactive transuranic element produced by bombarding plutonium with neutrons
  9. atomic number 17 a common nonmetallic element belonging to the halogens
  10. atomic number 67 a trivalent metallic element of the rare earth group
  11. atomic number 87 a radioactive element of the alkali-metal group discovered as a disintegration product of actinium
  12. atomic number 27 a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition
  13. atomic number 79 a soft yellow malleable ductile metallic element
  14. atomic number 93 a radioactive transuranic metallic element
  15. atomic number 37 a soft silvery metallic element of the alkali metal group
  16. atomic number 57 a white soft metallic element that tarnishes readily
  17. atomic number 91 a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
  18. atomic number 92 a heavy toxic silvery-white radioactive metallic element
  19. atomic number 98 a radioactive transuranic element
  20. atomic number 9 a nonmetallic univalent element belonging to the halogens