What element has the symbol 'La'?

The story behind the answer

La is the symbol for Lanthanum, element 57. It’s the first element of the lanthanide series (the rare earths). The distractors: Lead is Pb (from its Latin name plumbum), Lithium is Li, and “Lanthanide” refers to the whole series, not a single element.

Lanthanum is a soft, silvery metal discovered in 1839; its name comes from the Greek lanthanein, “to lie hidden,” because it was hard to isolate. Remember it this way: La launches the lanthanides—La starts the series. Or “LA = Lanthanum,” while Lead keeps its Latin Pb and Lithium keeps Li.