Earth and the Solar System: Phenomena: Question 3
How old is our solar system?
Select one:

1. About 13.5 million years.

2. About 13.5 billion years.

3. About 4.5 million years.

4. About 4.5 billion years.

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.