1. What is the difference between an atom and a compound?

A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons. An element is a substance that is made entirely from one type of atom. ... A compound is a substance made from two or more different elements that have been chemically joined

cock topography

the study of the surface of a large voluptuous cock.

look at that sorostitute right she's a cock topographer!

what classes are you taking this

cock topography!

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.