Question 14 unsaved a student says that all pure substances are elements. do you agree? why or why not? question 14 options: i disagree. all pure substances are also mixtures. i disagree. elements are not pure substances. all pure substances include only molecules and compounds, which are more complex. i agree. pure substances include only single atoms made of one element. i disagree. elements form all pure substances, but some pure substances include elements bonded together to form molecules and compounds.