HELP IM TIMED Which statements describe chemical changes? Check all that apply.

They change a substance’s properties.
They change a substance’s identity.
They can usually be reversed.
They keep a substance’s arrangement of atoms the same.
They change a substance into a different substance.

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.