History
Lanthanum was first discovered by a Swedish chemist named Carl Gustav Mosander in 1839; however, it was not isolated in pure form until 1923. It was discovered when Mosander was decomposing a sample of cerium nitrate. He did this by heating it up and then treating the salt that resulted with dilute nitric acid. From the solution that resulted from this, he found a new rare earth that he named lantana, meaning "hidden". The results of Mosander's findings weren't published for some time, and the experimental research with the lanthanum was continued for three years after it was discovered. Even after the results of the experiments were published and made public, the interest for lanthanum was purely scientific. It was almost a century until important applications for this element were discovered. Lanthanum is included in the lanthanides due to the fact that it's properties are similar to the other elements in the group; however, this particular element possesses a different electron configuration than any of the other lanthanides.
