Sulfur is often found in nature as an element, not combined with other elements in a compound. What does this fact tell you about the reactivity of sulfur?

sulfur is not a highly reactive element under ordinary conditions

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.