Answer: You can tell when a chemical reaction is taking place because it is usually accompanied by easily observed physical effects, such as the emission of heat and light, the formation of a precipitate, the evolution of gas, or a color change. All these things characterize what you look out for to find a chemical change.
Explanation:
Answer:
that one is hard because we did not see the vidoe
Explanation:
D. a cause might be the increase of survival rate of the long-legged ponies.
