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

These are not compounds:
(a) Chlorine gas
Chlorine gas consists of chlorine molecules. Chlorine is a non-metal.

(c) Iron


Iron is a metal.
(e) Aluminium


Aluminum is a metal


(f) Iodine
Iodine is a non-metal.
(g) Carbon


Carbon is a non-metal.


(i) Sulphur powder


Suphur is a non-metal.


Others are compounds because they are formed by the combination of different elements.


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