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Understanding the element
Thulium (Tm) is chemical element 69. 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 lasers, xray sources and scientific research.
lasersxray sourcesscientific research
Standard atomic weight168.934219(5)
What its position in the table tells us
Thulium 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
Thulium has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses
Thulium has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses