Polonium

Polonium was discovered in 1898 by Marie and Pierre Curie, the first of the two elements they found while investigating the intense radioactivity of pitchblende. It was Marie Curie's first discovery, and she named it polonium after Poland, her native country, which at the time did not exist as an independent state, having been partitioned among its neighbours. Polonium is a rare, intensely radioactive metalloid, a potent source of heat and alpha radiation. A milligram of polonium gives off enough heat from its decay to glow, and the isotope polonium-210 has served as a lightweight heat and power source in spacecraft and as an initiator in early nuclear weapons, though its extreme toxicity now sharply limits its handling.

Extracting polonium from pitchblende was a herculean task even by the Curies' standards: a tonne of the ore yields only about a tenth of a milligram of the element, a scarcity that meant visible, weighable quantities of polonium were not obtained for years after its existence was first inferred from its radioactivity. Trace polonium-210, absorbed by tobacco plants from phosphate fertilisers and soil, is also present in cigarette smoke, and some researchers have argued it makes a small but measurable contribution to the elevated lung-cancer risk of long-term smokers, a claim debated within toxicology but consistent with polonium's well-documented internal radiotoxicity.

The naming of polonium was a deliberate political act. Marie Curie chose to honour Poland, then erased from the map and divided between Russia, Prussia and Austria, in the hope of drawing the world's attention to her subjugated homeland; it is often described as the first element named to make a nationalist point rather than merely to record a place. The element has no ancient or alchemical tradition, being a product of the new science of radioactivity, but it gained a sinister modern notoriety in 2006, when polonium-210 was used to murder the dissident Alexander Litvinenko in London, a poisoning that made this obscure, heat-radiating element briefly world-famous. Its story runs from a scientist's patriotism to a notorious assassination.

Polonium was the first of the Curies' two new elements, announced in July 1898, five months before radium followed that December, so the deliberately patriotic name came first in a discovery sequence that would make Marie Curie, within a few short years, the most celebrated chemist of her generation and eventually a two-time Nobel laureate, in physics for the joint discovery of radioactivity and, separately, in chemistry for isolating radium and polonium themselves.