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Curium

Curium glows purple in the dark due to its intense radioactivity. This silvery-white metal was first synthesized in 1944 and named after Marie and Pierre Curie, pioneers in radioactivity research. Curium-244 is used as a power source in space probes, generating about three watts of thermal energy per gram — more than plutonium. Despite its usefulness in research, curium is highly toxic if absorbed, accumulating in bones and destroying red blood cell formation.

Curium was first revealed to the public on a children’s radio show before its official announcement a week later.