Polonium

About Polonium

Polonium was the first element Marie and Pierre Curie pulled out of pitchblende residues in 1898, isolating it by tracking the radioactivity rather than the chemistry. Marie named it after Poland — at the time partitioned out of existence — making the chemical literature carry a nationalist statement few editors noticed. The chemistry is what you'd predict for a heavy chalcogen sitting under tellurium: it forms PoO₂, PoCl₄, PoH₂, and a metallic α-phase with a simple cubic lattice (the only element that crystallizes that way at standard conditions). What sets it apart is the alpha activity. Polonium-210, the workhorse isotope and the easiest one to produce by neutron-irradiating ²⁰⁹Bi, decays with a 138-day half-life and a 5.4 MeV alpha that dumps about 140 W/g into anything stopping it — a pure gram self-heats to several hundred degrees Celsius. That heat is why early Soviet Lunokhod rovers used Po-210 thermal sources, and that biological devastation per ingested microgram is why Po-210 is the textbook example of a radiological assassination agent.