Question

If a sample of matter cannot be separated by physical means, what can be said with certainty about that sample?

A It is a pure substance.
B It is an element.
C It is a compound.
D It is a mixture.

Answer 1

A sample of matter that cannot be separated by physical means is a pure substance, which can be an element or a compound, both having constant compositions.

Step-by-step explanation:

If a sample of matter cannot be separated by physical means, we can say with certainty that the sample is a pure substance. This means that it is composed of either an element or a compound, both of which have constant composition and consistent properties throughout.

Compounds and elements are the simplest substances and they cannot be broken down into anything simpler by physical means. A mixture, on the other hand, can have varying compositions and can be separated into its component substances.