Beyond the answers - interesting background to this quiz

A rare element with a glowing name

Actinium, symbol Ac, sits at the top of the actinide series in the periodic table. It is named after the Greek word for ray, a nod to the radiation it emits. The element is found in trace amounts in uranium ores, and it glows faintly blue in the dark because of its intense radioactivity. Because it is so scarce and radioactive, actinium has few everyday uses.

The dove as an emblem of peace

The dove's association with peace has deep roots in Western culture, most famously in the biblical story of Noah, where a dove returns with an olive branch to signal that the flood is receding. Pablo Picasso later cemented the link in the modern imagination with his dove lithographs made for the World Peace Congress in the late 1940s. It is no surprise that doves appear on peace posters, stamps and monuments around the world.

Copenhagen and its Scandinavian neighbours

Copenhagen is the capital of Denmark and the country's largest city, sitting on the islands of Zealand and Amager. Aarhus, the second-largest city, is often mistaken for the capital by visitors. Across the water lies Oslo, the capital of Norway, which is often confused with Copenhagen because both are Scandinavian capitals with similar-sounding names. Denmark itself is the southernmost of the Nordic countries and shares its only land border with Germany.

The Horn of Africa and its neighbours

Ethiopia is a landlocked country in the Horn of Africa, bordered by Eritrea to the north and Djibouti to the northeast. Eritrea gained independence from Ethiopia in 1993 after a long conflict, and Djibouti, a small nation on the Gulf of Aden, sits at one of the world's busiest shipping straits. Ethiopia is also Africa's second most populous country and never experienced European colonial rule in the way most of its neighbours did.

A planet that rolls on its side

Uranus stands out among the planets for its extreme axial tilt, which is close to 98 degrees, meaning it essentially orbits the Sun on its side. Its magnetic field is similarly unusual: it is tilted by roughly 60 degrees from the planet's rotation axis and does not pass through the centre of the planet. This makes Uranus one of the strangest magnetic environments in the solar system. Only one spacecraft, Voyager 2, has ever flown past it.