Which of the following are not compounds?
(a) Chlorine gas
(b) Potassium chloride
(c) Iron
(d) Iron sulphide
(e) Aluminium
(f) Iodine
(g) Carbon
(h) Carbon monoxide
(i) Sulphur powder
Solution:
Elements – pure substance which cannot be broken down in simpler substance.
Chlorine, Iron, Aluminium, Iodine, Carbon and Sulphur Powder
Compounds – They are also pure, but can be broken down in constituents.
Potassium Chloride (KCl)
Iron Sulphide (FeS)
Carbon monoxide (CO)