The percent by mass of carbon in HC2H3O2 is equal to 1.
12
-X100
60
2.
24
--X100
60
3.
60
X100
24
4.
60
-X100
12

your parents i think this could be it

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.

1 is the answer to this problem