What happens to the charge of the atom if one electron is removed

if it loses an electron, it becomes positively charged

Explanation:

If electrons are removed from an atom, then it has more positive charges than negative ones, and the atom has an overall positive charge. Positive ions are called cations. The sharing or exchanging of electrons is what forms bonds between 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.