Beyond the answers - interesting background to this quiz

How Mercury ended up with such a stretched orbit

Mercury's orbit is the most eccentric of the eight planets, meaning its distance from the Sun varies considerably over a single trip around it. That orbit also explains a famous milestone in physics: small discrepancies in Mercury's motion, which Newtonian gravity could not fully account for, were resolved by Einstein's general theory of relativity. The planet's orbital quirks made it a natural testing ground for a new way of thinking about gravity.

Why some vitamins stay in the body longer than others

Vitamin A is one of the fat-soluble vitamins, along with D, E and K, which means the body can store it in the liver and other tissues rather than flushing out what it does not need right away. Water-soluble vitamins such as vitamin C and the B group behave differently: excess amounts are largely excreted in urine, so they need to be replenished more regularly through the diet. That difference shapes everything from how often deficiencies appear to how quickly they develop.

From Persia to Iran: a name with deep roots

Iran was known internationally as Persia until 1935, when the government asked foreign countries to use the name Iran, the term its own people had long used. "Persia" traces back to Pars, a region in southern Iran, and to the ancient Achaemenid Empire, which at its height stretched from the Balkans to the Indus Valley. The older name still lives on in references to Persian language, art and carpets.

Mandela's presidency and a turning point for South Africa

Nelson Mandela became president of South Africa in 1994, following the country's first democratic elections in which Black South Africans could vote. He had spent 27 years in prison for his opposition to apartheid before his release in 1990. His single term as president, from 1994 to 1999, focused on reconciliation and rebuilding institutions in a deeply divided nation.

The smallest state that still looms large

Rhode Island is the smallest US state by area, yet its official name, "State of Rhode Island and Providence Plantations," was among the longest of any state until voters shortened it in 2020. Despite its size, it played an outsized role in early American industry, particularly in textile manufacturing and the slave trade centred on the port of Bristol and Providence.