Question

which best describes a compound such as sodium chloride?
a pure substance that can be separated into different elements by physical means
a mixture of two common substances that can be separated by chemical means
a mixture of two common elements that can be separated by physical means
a mixture of two common elements that can be separated by chemical means
a pure substance that can be separated into different elements by chemical means

Explanation:

A compound like sodium - chloride is a pure substance made up of two or more elements (sodium and chlorine in this case). Compounds can only be separated into their constituent elements by chemical means, not physical means. Physical means are used to separate mixtures.

Answer:

a pure substance that can be separated into different elements by chemical means