what are the four signs of a reaction?

Question

this question has to do with chemistry.

Answer 1

bubblilng, change of color, change of temperature, rusting
although i don't know if those are the exact four, but those are examples or some signs

Answer 2

You can take any of the physical properties and put "change in" in front of them and get signs that a chemical reaction occurred.

Examples: change in state (shown by bubbling, a precipitate forming), change in color (not art, but a true change), change in odor, change in density, change in optical properties, etc, etc. Also burning is a good sign, light given off and sound given off.

Go get an "A"!!!!