Beyond the answers - interesting background to this quiz

The element that waited more than a century for its name

Neodymium, symbol Nd, belongs to the lanthanide series of rare earth elements. It was first isolated in the late nineteenth century, but it took until 1925 for a pure sample to be presented, which is when it received the name it carries today. The name itself comes from Greek words meaning "new twin", a reference to how closely it resembles another rare earth element, praseodymium. Neodymium is not just a laboratory curiosity: it is used in powerful magnets found in headphones, hard drives and wind turbines.

A rice dish that became a national symbol

Paella originates in Valencia, on Spain's eastern coast, where it was traditionally cooked over an open fire in a wide, shallow pan that gives the dish its name. The original Valencian version contains rabbit, chicken and sometimes snails rather than the seafood many people associate with paella today. The dish is closely tied to the region's rice-growing history and to the social ritual of cooking and eating it outdoors with family and friends.

The river that links three countries

The Danube is one of Europe's longest rivers, and it passes through Germany, Austria and Hungary on its long journey eastward. It flows through four capital cities in total, more than any other river in the world. Vienna, Bratislava, Budapest and Belgrade all sit on its banks. The river has served as a trade route, a border and a source of inspiration for composers and writers for centuries.

A city that is not a capital, despite the crowds

Denpasar is the capital of Bali province in Indonesia, but it is not the capital of the country. Indonesia's capital is Jakarta, located on the island of Java. Denpasar is the largest city on Bali and a major gateway for the millions of tourists who visit the island each year. The confusion is understandable: Denpasar functions as an administrative and economic hub for the region, much like a national capital would.