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Understanding the element
Promethium (Pm) is chemical element 61. It belongs to the lanthanoids, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.
Where do we encounter it?
In practice, it turns up most often in nuclear batteries, scientific research and luminous paint.
nuclear batteriesscientific researchluminous paint
Standard atomic weightNo standard atomic weight
What its position in the table tells us
Promethium sits in period 6 and the F block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.
Worth remembering
Promethium is radioactive, so its chemistry cannot be separated from nuclear physics and radiation safety
Promethium is radioactive, so its chemistry cannot be separated from nuclear physics and radiation safety