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All 118 elements

Element 84 ·post-transition metal

pō — "polonium"

Polonium

Traditional:

How the character is built

The radical marks this as a metal, and that is not a coincidence of this one character — it holds right across the table. Read the radical first and the element's state at room temperature is already settled. It is (jīn) squeezed into the space beside another component — radicals change shape by position, which is why is hard to spot until you know to look for .

Phonetic 卜 (usually bǔ), read pō here for the 'po-' of polonium.

This character is used for the element and little else — you are unlikely to meet it outside a chemistry classroom.

The element itself

Polonium is present in uranium ore at concentrations that beggar belief — a matter of micrograms per tonne — and Marie and Pierre Curie found it not by seeing it but by noticing that a particular chemical fraction of their residues was far more radioactive than the uranium in it could account for. It is intensely radioactive, giving off enough energy from its own decay that a sample warms visibly and can glow from ionised air around it. It was named for Poland, which at the time did not appear on the map as an independent country.

Where it sits among the 118

Polonium melts at 254°C (527 K) — lower than 71 of the 97 elements whose melting point has been measured, and higher than 25. The grey dots are the rest of the table.
In the Earth's crust there is present only in traces, far below a milligram per tonne. That makes it commoner than 6 of the 93 elements that occur naturally at all. The scale is logarithmic: each gridline is ten times the one below it.

First isolated in 1898.

The full entry

For stroke order, example sentences, audio and the complete set of meanings, see the dictionary entry.

Polonium in the dictionary →

Others built the same way

Every one of these carries , and every one is a metal.

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