The hypothetical ion aso three- is a polyatomic ion with arsenic atom as a central atom how many valence electrons does a compound have

3 valency electrons.

Explanation:

Arsenic has 5 valency electrons and oxygen has 6.

In the  AsO  radical,  the oxygen  can accepts 2 electrons so the number of valency electrons = 5 - 2 = 3.

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.