If a gas at 4.5 atm expands to 3.0 L, what will the volume be at 13 atm?

1.04 L

Explanation:

4.5 atm x 3 L/13 atm

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.