Which of the following states is NOT correct about "STP?" a. The standard temperature is 25 °C.

c. The standard pressure is 1 atm.

c. standard
pressure is 101.3 kPa

d. At STP, a gas has 22.4 L as its volume.

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.