Although curious chloride is not the most popular name for curium and chlorine, it’s actually an official name. And true to its name, this substance has a slightly-whimsical, slightly-sinister property — which actually might be useful when making soup.

Curium was not discovered by Marie Curie. If it had been, it probably would not have been named for her. (Many scientists consider naming your discovery after yourself tacky, though if I ever discovered anything, I would totally do it.) It was discovered by Glenn Seaborg, a Berkeley physicist who spent much of World War II hitting uranium with neutrons to build a new element, and then found himself unable to publish until peace time.


After news of the new element got out, people naturally started playing around. They found that curium would combine readily with three chlorine atoms, to make curium trichloride. Compounds with curium in them have a lot of different names, and chemists have a playful nature. (That goes all the way back to Humphry Davy experimenting on himself with laughing gas.) There are multiple names for compounds with curium, including curates (as in members of the clergy), curous, and curious.

Although rarely found in texts, the “curious” name caught on, and curium trichloride was known, for a while, as curious chloride. And it does have one curious property: It’s extremely radioactive.


The neutron bombardment that Seaborg used made a new element, not a stable one. As curium comes apart again, it gives off energy. It gives off so much energy, that if you add enough of it to a liquid, the liquid will boil. So if you were to add curious chloride to your soup, it might not improve the taste, but it would actually cook the soup for you.

Image: Alvin de Castro Chan