Due to lanthanide contraction, yttrium, which is trivalent, is of similar ionic size to dysprosium and its lanthanide neighbors.
en.wikipedia.org Whereas trivalent europium gives red phosphors, the luminescence of divalent europium depends on the host lattice, but tends to be on the blue side.
en.wikipedia.org There are five products available through the province's flu program -- two of the five products are quadrivalent, meaning they can safeguard against four strains -- and three are trivalent.
www.theglobeandmail.com The trivalent americium forms insoluble fluoride, oxalate, iodate, hydroxide, phosphate and other salts.
en.wikipedia.org Like all actinides, berkelium easily dissolves in various aqueous inorganic acids, liberating gaseous hydrogen and converting into the trivalent oxidation state.
en.wikipedia.org