Describe three signs that a chemical reaction has taken place and give an example of each sign

Color change, temperature change, bubbling, state change

green to blue, hot to cold, bubbles (lol), and liquid to gas

The third choice .. (:

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)