Which of the following are NOT a sign of a chemical reaction?

D.

Shape for sure, if a squished a piece of gum, it changes shape, but my hand never chemically reacted with it. Shape is a physical and not a chemical property of elements. If it was a phase change, that would be totally different (like going from a solid to gas)

All the other's you listed are chemical properties of elements, so when a chemical reaction occurs they are bound to as well.

Hope that helps!

all of the above. word: that's an illustration of a chemical reaction, yet no longer a adequate situation. hearth burning--chemical reaction, torch gentle, --no longer a chemical situation. warmth flow by radiation, convection, and conduction, might or won't an illustration of a chemical reaction.

A. Change in odour.

Quite easy, just mix two chemicals together and observe what happens.

Shape change is the correct answer.

I would have thought change in temperature.. Hope I helped