|Paris—Marie Curie, Pierre Curie elements
Pierre and Marie Curie analyzed pitchblende which they knew contained radioactive uranium. They removed the uranium, and separated the residue into salts of bismuth and salts of barium. From the bismuth fraction they isolated a substance that was four hundred times more radioactive than uranium. They named it after Poland, Marie’s native land, then under occupation, and their finding was questioned until well into the next century.
Atomic number 84
Polonium is dangerous with no biological redeeming purpose. It occurs naturally as a step in the decay chain of uranium-238 and is derived unnaturally from lead-bismuth coolants used in nuclear power plants in Russia. Polonium-210 has a half-life of 138 days too brief to use as a power source for planetary and interplanetary probes.
Different isotopes for different folks
Dmitri Mendeleev predicted polonium and called it dvi-tellurium. Friedrich O. Giesel thought polonium was a radioactive form of bismuth and called it radiobismuth. William H. Bragg and Richard D. Kleeman found polonium-218 and called it radium-A. Hans W. Geiger, Ernest Marsden, and Ernest Rutherford found polonium-216 and called it thorium-A. Hans W. Geiger and Ernest Marsden found polonium-215 and called it actinium-A. Otto Hahn and Lise Meitner, and Kasimir Fajans found polonium-214 and called it radium-C. Otto Hahn found polonium-212 and called it thorium-C. Ernest Marsden and R. H. Wilson found polonium-211 and called it actinium-C. Willy Marckwald found polonium-210 and called it radiotellurium.