noun Download 🔗Share A chemical element (symbol La) with an atomic number of 57: a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. Examples : "The chemistry student learned that lanthanum is a silvery metal used in some camera lenses. " element substance material chemistry science Chat with AIVocabulary GamePractice Reading
noun Download 🔗Share An atom of this element. Examples : "The chemistry student pointed to lanthanum on the periodic table and said, "An atom of lanthanum has 57 protons." " element chemistry substance material science Chat with AIVocabulary GamePractice Reading