Beyond the answers - interesting background to this quiz

The river that drains a fifth of Europe

The Volga is not just the longest river in Europe - it is also the largest by discharge, emptying into the Caspian Sea. It winds through forests, steppe and major Russian cities, and it has carried trade and transport for centuries. The Danube, by contrast, flows through more countries than any other river in the world, which is why it is often called Europe's most international waterway.

An element named for its glow

Radium's symbol, Ra, comes from the Latin word "radius", meaning ray, a nod to the eerie glow its compounds give off in the dark. Marie and Pierre Curie discovered it in the late 19th century while processing pitchblende ore, a painstaking effort that helped earn them a Nobel Prize. For years radium was treated as a wonder substance, used in glow-in-the-dark watch dials and even tonics, before its dangers became clear.

A painter of anxiety

Edvard Munch described "The Scream" as an infinite scream passing through nature, inspired by a moment when he felt "a great, unending scream" while watching a sunset. He created several versions in different media, and the composition has become one of the most recognisable images in art. Munch's work often explored fear, grief and isolation, themes that shaped his entire career.

An ocean giant built for krill

The blue whale is the largest animal known to have lived, bigger than any dinosaur. Despite its size, it feeds mainly on tiny krill, filtering huge volumes of water through baleen plates. Its calls are among the loudest sounds produced by any animal, capable of travelling long distances underwater.

A capital beneath the mountains

Tehran sits at the foot of the Alborz mountains in northern Iran, a location that shapes both its climate and its skyline. It became the country's capital in the late 18th century and has grown into one of the largest cities in the Middle East. The city's position makes it a gateway between the dry interior plateau and the greener slopes to the north.