They use information from other things that relate to that topic and then use that to do their research
Chemical changes only happen when the object changes form. Color is a physical property because you're not changing the object that you have, compressibility is also a physical property because you still have the same substance before and sfter, malleability again is another physical. Heat of combustion is physical, when you burn things it changes the substance. :)
A. It can be as important to a story as a character
