Is there are a total of 7.3 x 10^29 atoms in a sample of glucose, c6h12o6(s),what amount in miles of glucose is in the sample?

(7.3 x 10^29 atoms) / (24 atoms/molecule) / (6.022 x 10^23 molecules/mol) =  

5.1 x 10^4 mol C6H12O6

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.