Multiple Choice Question

Question

A student wrote a table comparing pure substances and mixtures.

Pure Substances Mixtures
elements and compounds
cannot be separated using physical means
contains two or more substances
are chemically combined
The student made a mistake on their table. Which statement best describes the mistake made?

A.
Elements and compounds are considered mixtures.

B.
Mixtures contain at least three or more substances.

C.
Pure substances can be separated using physical means.

D.
Mixtures are substances that are not chemically combined.

Answer 1

The correct answer is:

D. Mixtures are substances that are not chemically combined.

This statement best describes the mistake made by the student. In their table, the student inaccurately stated that "pure substances" contain elements and compounds, which is not wrong, but it could imply a misunderstanding that elements and compounds have similar properties to mixtures. The key distinction is that mixtures consist of two or more substances that are not chemically combined, while pure substances consist of only one type of particle, either an element or a compound.