Beyond the answers - interesting background to this quiz

A capital at the crossroads of empires

Belgrade sits where the Sava meets the Danube, a position that has made it strategically valuable for centuries. It has been fought over and rebuilt many times, changing hands between empires and states. Today it is the capital of Serbia and one of the larger cities in southeastern Europe.

A famous family resemblance

Angelina Jolie is the daughter of actor Jon Voight, who won an Academy Award for his role in Coming Home. Her parents separated when she was young, and she was largely raised by her mother. Despite a famously complicated relationship over the years, father and daughter have worked together on screen, including in Lara Croft: Tomb Raider.

The smallest planet and its scorching neighbour

Mercury is the closest planet to the Sun, orbiting it in just 88 Earth days. It is also the smallest planet in our solar system. Venus, though farther out, is actually the hottest planet because of its thick atmosphere and runaway greenhouse effect.

The metal that flows

Mercury is the only metal that is liquid at ordinary room temperature. This property, along with its silvery shine, earned it the nickname "quicksilver". It was long used in thermometers and barometers, though concerns about its toxicity have led to many of those uses being phased out.

A ball so light it barely registers

Table tennis uses one of the lightest balls in any sport, weighing only about 2.7 grams. That lightness is part of why the game is so fast and spin-heavy. By contrast, pool balls are solid and heavy, and korfball uses a ball closer to a volleyball in weight.