Lanthanum

Lanthanum is the first of the lanthanides, a group of 15 elements that were so hard to separate from each other that they drove chemists crazy for over a century. Discovered in 1839 by Carl Gustaf Mosander, its name comes from the Greek 'lanthanein,' meaning 'to lie hidden' — appropriate since it was hiding inside another element's mineral sample.

Lanthanum is used in hybrid car batteries (nickel-metal hydride batteries in the Toyota Prius contain lanthanum), camera and telescope lenses that reduce distortion, and lighter flints — the spark from a cigarette lighter comes from a lanthanum alloy called mischmetal. Lanthanum carbonate is used as a medicine to treat kidney patients by removing excess phosphate from their blood.

Lanthanum's symbol 'La' is a top-tier two-letter element in Spellement. It matches the start of words like 'last,' 'late,' and 'land,' fitting one of the most common English letter pairs. This makes lanthanum one of the most intuitive and useful elements for word building.