Question

Which of the following illustrations represents a pure substance? Why?

Answer 1

`"Option C"`

Explanation:

Good question. A pure substance contains only the ONE type of atom or molecule. Pure substances can be elements or compounds.

`A` depicts at least two types of substance, a diatomic molecule, `X_2`, and a heteronuclear diatomic, `AX`; `B` depicts single atoms, and another heteronuclear diatomic; `D` depicts the same as `B`.

For `C`, however, only the one type of heteronuclear diatomic is present. Reasonable examples would include `HX` or `CO`.