What is a covalent compound? A. a compound with a metal and a nonmetal ion sharing valence electrons
B. stable group of multiple metal nuclei sharing valence electrons
C. a compound with nonmetal ions transferring valence electrons
D. a stable group of more than one type of atom bonded by bonding electron pairs

jsjegsgshsygegeheh8w8wi

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.