While studying chemical and physical changes, students added salt to a glass of water. they stirred the salt until it dissolved and could no longer be seen. "that's a chemical change," sarah stated. do you agree? explain. a) yes, it is a chemical change because something new is formed. b) no, it is a physical change. it is salt and water and you can get the salt back by boiling off the water. c) yes, it is a chemical change because there was a change in the appearance of one of the components, the salt. d) no, it is a physical change. a chemical change cannot occur when you mix two compounds together like salt, nacl, and water, h2o, without adding heat.