Term: lanthanum (La)
Literally meaning: “pertaining to hidden”
λανθάνω/lanthano(= to be hidden, to escape notice) .
The element called lanthanum because it is “hidden” in rare minerals.
Lanthanum was isolated in the mineral cerite, by Swedish chemist Carl Gustav Mosander (1797-1893) in 1893. The name lanthana, that was first given to the new element, was suggested by Swedish chemist and his friend Jons Jacob Berzelius in 1817 ((1779-1848). Mosander announced the discovery of another rare earth contained in it that he named “didymium” because it seemed to be “an inseparable twin brother of lanthanum”.
Lanthanum is a chemical element wit atomic number 57 and atomic mass 138.90547. It is a moderately toxic element with soft silvery-white appearance. It is used in nickel metal hydrite (NiMH)rechargeable batteries for hybrid automobiles.