Containing three of the four elements named after the same town in Sweden, FTP, identify this group of 15 elements that includes Erbium, Samarium, Promethium and its namesake element whose name comes from the Greek word for "to lie hidden".
Commercial uses for these include uses in lasers and in sunglass lenses as they tend to reflect harmful UV radiation as well as several members of this group comprising significant portions of the alloy called Misch metal. Due to their electronic structures, members of this group tend to lose three electrons and are therefore find their most stable oxidation states as trivalent ions. Trends among this group include the filling up of the 4f atomic orbital and a decrease in the size of the ionic radius, the group's namesake 'contraction'. Containing three of the four elements named after the same town in Sweden, FTP, identify this group of 15 elements that includes Erbium, Samarium, Promethium and its namesake element whose name comes from the Greek word for "to lie hidden".
Commercial uses for these include uses in lasers and in sunglass lenses as they tend to reflect harmful UV radiation as well as several members of this group comprising significant portions of the alloy called Misch metal.
{Lanthanides}  