Question

Which of the following statements are true for pure substances?
(i) They contain only one kind of particles.
(ii) They can be compounds or mixtures.
(iii) They have the same composition throughout the substance.
(iv) They are formed by the physical combination of substances.

• A. (i) and (ii)
• B. (iii) and (iv)
• C. (ii) and (iii)
• D. (i) and (iii)

Answer 1

The correct option is D (i) and (iii)

Pure substances are made up of only one kind particles. They have the same composition throughout the sample. They cannot be further broken down into simpler substances.
Elements and compounds are pure substances. Whereas mixtures cannot be considered as pure, since they are formed by the physical combination of substances.