Aneutral beryllium atom has four protons and five neutrons. how many electrons does it have?

4.5 electron because you have to add the proton and the electron and then divide by two.

Four electrons

Explanation:

Neutrons are neutral (have no charge), while protons have a positive charge and electrons have a negative charge with the same magnitude as the proton's charge. For an atom to be neutral, the positive and negative charges must cancel, so the number of electrons must equal the number of protons.

the answer is alpha particles hope i you

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.