Question: what is your favourite periodic element?

  1. Mercury, or quicksilver as it was called in “the old days.”

    It’s a metal and so has metallic properties, but it’s a liquid at room temperature and so it is very versatile. Before we knew that it could be toxic it was used for all sort of things especially scientific equipment. Some examples are thermometers, weights, electrical switches, polishes and light bulbs. Today it is still used in some of the light bulbs used in projectors and mercury thermometers are still the best.


  2. Probably caesium. It elongs to the Group I elements in the periodic table, they used to be called alkali metals. All of the alkali metals – like sodium,potassium and caesium have similar properties – they are highly reactive, they are soft and silvery in colour. Caesium is a liquid metal at 28oC – so if it gets a bit hot in summer it turns into liquid. But I like it because when it reacts with water it’s explosive! Huge fun to watch..behind a safety barrier.