You need 2.5 moles of aluminum for an experiment. How many atoms of aluminum is this?

1.505×10^24 atoms

Explanation:

1mole=6.02×10^23 atoms

2.5moles=?

(crossmultiply)

2.5×6.02×10^23 ÷1

=1.505×10^24 atoms

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.