Beyond the answers - interesting background to this quiz

Why sodium hides behind "Na"

Sodium's chemical symbol, Na, comes from natrium, the Latin name for the element. That is why it looks nothing like the English word: the symbol was fixed by international convention based on older Latin terminology, while the name changed in modern languages. The same pattern explains why iron is Fe (from ferrum) and lead is Pb (from plumbum).

The only apparatus shared by both gymnastics programmes

At the Olympics, men and women compete on different sets of apparatus, but floor exercise appears in both programmes. Men also compete on pommel horse, rings, vault, parallel bars and horizontal bar, while women take on vault, uneven bars and balance beam. Floor routines differ in style and music, but the event itself is common ground.

Roof of the world, and a giraffe's reach

The Pamir Mountains, often called the "Roof of the World", lie mainly in Tajikistan, with parts extending into Afghanistan, China and Kyrgyzstan. Further south, the Andes run along the western edge of South America, with Colombia among the countries they cross. Both ranges shape the climate, wildlife and cultures of the regions around them.

Homer and a tale told for nearly three thousand years

The Odyssey is attributed to the Greek poet Homer, who is also credited with the Iliad. The poem follows Odysseus on his long journey home from the Trojan War, encountering monsters, gods and temptations. It has influenced countless later writers, and words like "odyssey" now describe any long, eventful journey.