I am writing about an element known as lanthanum. The name comes from the greek word lanthano, meaning to be hidden or concealed. It was discovered by the Swedish chemist Carl Mosander in 1839. It has the atomic weight of 138.91 and the atomic number of 57. It is found with other rare earth’s in monazite, bastnasite, and other minerals. Monazite and bastnasite are principle ores in which lanthanum occurs in percentages up to 25 and 38 percent. Misch …showed first 75 words of 423 total…

…showed last 75 words of 423 total…of glass, and is used in making special optical glasses. Cast iron can also be produced when using lanthanum as an additive.. There is a resent interest in hydrogen sponge alloys containing lanthanum. These alloys take up to 400 times their own volume of hydrogen gas. When handling lanthanum there should be some caution taken. Lanthanum and its compounds has an acute toxicity rating. This metal can cost up to two dollars a gram. ------------------------------------------------------------------------ **Bibliography**