QUESTIONS

Q : Are some elements becoming so scarce there may soon be gaps in the Periodic Table?

Graham Eden, Morecambe, Lancs.

Q : Floating pennywort is an invasive species clogging up Britain’s waterways. Where did it come from? How is it being dealt with?

Laura Ingram, Norwich, Norfolk.

Q : Did a Boy Scout once build a nuclear reactor in his garden?

Charles Taylor, Ely, Cambs.