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Articles from Britannica encyclopedias for elementary and high school students.
- Terbium - Student Encyclopedia (Ages 11 and up)
silvery-white rare-earth metal element soft enough to be cut with a knife. Found in cerite, monazite, and gadolinite and as a product of nuclear fission, it is used in certain solid-state devices. One compound is used as a laser material. The oxide is a dark maroon color. It was discovered in 1843 by Carl Gustaf Mosander in mineral yttria.