Name the substance that can a reaction to proceed without being used up in the reaction.

answer; /// the amount of material dissolved in a measure of liquid(concentration) the above statement is (true); /// good luck

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.