You are given a sample of an unknown aqueous substance. after performing several tests on the compound, you discover that it turns blue litmus paper red and that reacts with sodium hydroxide (naoh), which is a base, to form a salt (nacl) and water. as a result, you conclude the unknown substance to be:

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.

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter