You are right, it's CA Calcium, 40.08, Group 2 and Row 4.
The answer is 4.69 x 10⁻¹⁹ I hope this helped!
The best answer for the question above would be the chloroflourocarbons or the CFCs. These chloroflourocarbons or CFCs are the ones responsible for the depletion of the ozone - which leads to leaving a hole in its layer. These gases eat out the ozone layer and allows harmful UV rays of the sun to come in the Earth.
The process which has taken place is called CRYSTALLIZATION.
Generally, crystallization is the process by which solid crystals are precipitated from solution. Crystallization can also occur when a crystal melt or when a crystal get deposited directly from a gas, although these cases are rarer compare to crystals forming from solutions.
B is the answer to your question