I. J Thomson’s experiments provided evidence that an atom _.

answer:

C

Explanation:

J.J. Thomson was actually the discoverer of electron and thus provided evidence that an atom contain negatively charged particles

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.