haruldaste muldmetallide hulka kuuluv radioaktiivne keemiline element, järjenr 61
a rare, radioactive, metallic chemical element of the lanthanide series, atomic number 61, which was first produced artificially in a nuclear reactor and is present in trace amounts as a fission product in uranium ores
The known uses of promethium are due to its radioactivity. Its soft beta-particle radiation can be converted to electricity in miniature batteries formed by sandwiching promethium between wafers of a semiconductor such as silicon; those batteries operate in extreme temperatures for up to five years. Other uses are as beta-radiation sources—e.g., in light sources that use phosphors to absorb beta radiation and convert it to visible light.
