Beyond the answers - interesting background to this quiz

The extremes of the American landscape

Death Valley holds the record for the lowest point in the United States, sitting roughly 86 metres below sea level. It is also one of the hottest places on Earth, with summer temperatures that regularly climb above 45 degrees Celsius. Despite the harsh conditions, the valley supports resilient plants and animals, and its striking salt flats draw visitors from around the world.

A capital city with a knightly past

Valletta, the capital of Malta, is one of the smallest capitals in Europe, yet the entire city is a UNESCO World Heritage Site. It was founded in the 16th century by the Knights of St John and named after their Grand Master, Jean de Valette. Its grid of narrow streets, fortifications and baroque churches reflects centuries of Mediterranean history.

Why the sky is not simply blue

The blue colour of the sky comes from a phenomenon called Rayleigh scattering. Sunlight is made up of many wavelengths, and when it passes through the atmosphere, shorter blue wavelengths scatter far more than longer red ones. That scattered blue light reaches our eyes from every direction, which is why we see a blue sky rather than a dark one.

From ancient China to the battlefield

Gunpowder is believed to have been invented in China, with early recipes recorded by the 9th century. It began as an accidental by-product of alchemical experiments in search of an elixir of life. Over time, its explosive properties were harnessed for fireworks, weapons and, eventually, warfare across the world.

A city built on water

Venice sits on the Adriatic Sea, on a cluster of small islands in a lagoon in north-eastern Italy. Instead of roads, the city relies on canals and bridges, with boats serving as everyday transport. Its unique setting has made it vulnerable to flooding, and the city has invested in barrier systems to protect it from high tides.