# What metals are a collection of seventeen chemical elements in the periodic table, specifically the fifteen lanthanoids, plus scandium and yttrium?

$\text{The lanthanides....}$
The lanthanides, $Z = 58 - 71$, and the Group 3 metals, scandium, yttrium, and lanthanum, all routinely form largish ${M}^{3 +}$ cations, with very similar chemistries...