You heat two substances, A and B. Both substances change color. When cooled, substance A returns to its original color, but substance B does not. What most likely happened in this situation? A chemical change occurred in both substances. A physical change occurred in substance A, and a chemical change occurred in substance B. A physical change occurred in both substances. A chemical change occurred in substance A, and a physical change occurred in substance B.

i believe it is a.) released into

explanation:

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante