Promethium belongs in the 7th family. The 7th family is The Lanthanide family.
Promethium is a lanthanide; a very rare, natural (but also artificially obtained), radioactive chemical element.
Promethium is placed in the period 6 of the periodic table, lanthanoids family.
sex on the beach lol jk its 6
The lanthanides, but it does not fit in as well
Promethium is one of the lanthanoids, atomic number 61, period 6.
Promethium is a metal in the family of lanthanoids.
promethium
Promethium is a member of the lanthanoids family.
Promethium is a member of the lanthanoids family.
niobium period
Promethium is a chemical element from the lanthanoids family, with the atomic number 61, metal, radioactive.
It belongs to the 7th period, the halogens.
Einsteinium is a member of the actinoids family (period 7).