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Each of these is a quiz question in its own right, but the answers connect to a common theme, which could be anything from plumb straightforward to bizarrely lateral 2 Which element, one of only five metals that are liquid at room temperature (the other four being rubidium, francium, gallium and mercury), is used in the making of atomic clocks? 3 John Snow was the first to successfully use what element to disinfect the water 1 In Pepto-Bismol, a drug used to treat minor stomach upsets, what does the ‘Bis’ stand for? supply in Soho, London, to stem the spread of an 1854 cholera outbreak? 4 In higher animals what is required for synthesis of thyroid hormones, of which this element is a necessary ingredient? 5 The primary use of which element is as a catalytic converter in automobiles, where it changes harmful unburned hydrocarbons, carbon monoxide, and nitrogen oxide emissions from the engine into less noxious gases?