300 grams of an organic sample which contains only carbon, hydrogen and oxygen is analyzed and found to contain 145.946 grams of carbon, 24.3243 grams of hydrogen and the rest is oxygen. What is the empirical formula for the compound?

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.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.