As pressure decreases so does boiling point. one reason astronauts wear space suits in space is because of the decreased pressure in space. explain what might happen to the blood of an astronaut subjected to extremely low pressures.

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.

the answer to this question is 3.