Which of these charges has the greatest magnitude

magnitude means absolute value, so the one that is greastest, like |-7| and |4| even id |-7| is a negative number, but it is still the one farthest away from 0, so |-7| is greater than |4|.

That is the way to find the greatest magnitude, but because I don't know your numbers so I can not answer your question, but this is the way to solve for it.

HOPE THIS HELPS( IF IT DOES PLEASE MARK ME AS BRAINLIEST )

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.