The bar chart below shows data for a system with two types of particles, x and y, in two connected regions, A and B. All of the x particles started in region A, and all of the y particles started in region B. Which line graph best depicts the data in the bar chart?

C.

Step-by-step explanation:

We have two types of particles, x and y and two regions, A and B. The enunciated says that at the beginning all x particles are in A and all y particles are in B. Then, at the beginning, the 100% of x particles are in A and 0% of y particles are in A. So, the option A is discarded.

Now, the right part of the picture shows that after a while, 12 x particles go from region A to region B and 12 y particles go from region B to region A. Then, the percentage of x particles en region A will decrease and the percentage of y particles in region A will increase. That situation leaves us only with options B and C.

Finally, there will be 38-12 = 26 x particles in region A after the time and 12 y particles in region A. 26 and 12 represent two different percentages of 38 (the total) so, the graphs don't join. So, the answer is C.