Question

pure substances pure substances have a fixed chemical composition. every molecule is the same. the substance has a constant composition throughout. these substances cannot be separated into simpler components by physical means. what does “fixed chemical composition” mean? every molecule is the same constant composition throughout cannot be separated by physical means all of the above

Explanation:

The text states fixed - chemical composition means every molecule is the same, constant composition throughout, and not separable by physical means.

Answer:

D. all of the above