It depends. many of the websites i see answering the questions are all over the place, but good luck.
Answer:
C. At some point, the land was covered in water.
Explanation:
In the diagram it shows the different fossil layers. In the bottom layers there are shells, but as you go up the fossils start changing. This shows that there used to be water there, but now it is land.
Use formula n= number of particles / avogrado constant
n= number of mole
avogrado constant= 6.12x10^-23
you will get 2.042 x 10^52
