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.
The functional group can affect the chemical properties and physical properties. Like CH3CH3 and CH3CH2OH. The first one is gas and second one is liquid. The first one is not easy to react with others while the second one is.
Moles of water atoms = mass/molecular weight = 105/18 = 5.83 mol. Number of moles of hydrogen in water = 2 x moles of water = 11.66. Number of H atoms in water = moles of hydrogen x 6.02 x 10^23 = 7.019 x 10^24 ~ 7.02 x 10^24 atoms. Hope this helps.