Which symbol represents an atom in the ground state with the most stable valence electron configuration?
(1) b (3) li
(2) o (4) ne

Explanation: The stable valence configuration is one in which the orbitals are completely filled as they are least reactive. Elements with partially filled valence shells are less stable and more reactive as they tend to gain or lose electrons to acquire stability.

43.452

step-by-step explanation:

284 times .153 = 43.452

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.