Number 1 please fast answer

Answer:
I will give you 5
Explanation:
color chage, formation of a precipitate, formation of a gas, odor change, temperature change. are all signs of a chemical reaction
Answer: Color change, Production of odor, and
Temputure change, formation of bubbles, and form of solids
Explanation:
It basic chemistry , as in if the solution has changed it would express itself in these ways otherwise it would not make the list.