Ibeg you i realy need when the characteristics or state (solid, liquid or gas) of a substance change but the chemical composition does not change that is an indication of: a physical change a chemical change a global change no change which of the following is an extensive physical property of matter? volume viscosity odor density the percentage by mass of elements in a particular pure substance will vary from sample to sample. true false classify each of the following as an element, compound, or mixture. mixture compound element answer a. propane gas b. soil (dirt) c. solid gold coin