Question 7 from the 2015 Australian Chemistry Olympiad was:
Which list below gives non-metals that can be found in their elemental form in nature?
(a) neon, phosphorus, fluorine
(b) helium, hydrogen, iodine
(c) helium, carbon, fluorine
(d) nitrogen, chlorine, sulfur
(e) oxygen, chlorine, phosphorus
I was somewhat confused when all the options included reactive elements such as sulfur, phosphorus and the halogens. I know neon is a noble gas and is present in minute quantities in the atmosphere, and nitrogen and oxygen gases are present as diatomics.
However, where are hydrogen, phosphorus, sulfur, fluorine, chlorine and iodine found in their elemental forms in nature? (Answer is B)