Question: What is the most useful element?

Pete Etchells answered on 14 May 2012:

Depends what you mean by useful! Oxygen is obviously very useful, as without it wouldn’t be able to breathe! I guess one of the most useful elements is copper, though – it’s used in everything from electricity cables to coins to being used as a roofing material in buildings. It’s also used in motors, and as a wood preservative! It’s also got antimicrobial properties – so copper doorknobs are particularly good because bacteria find it hard to stay on the surface.