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Understanding the element
Thallium (Tl) is chemical element 81. It belongs to the post-transition metals, 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 electronics, optics and scientific research.
electronicsopticsscientific research
Standard atomic weight[204.382, 204.385]
What its position in the table tells us
Thallium sits in period 6, group 13 and the P block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.
Worth remembering
Thallium has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses
Thallium has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses