Iodine electron configuration is:
1S^2 2S^2 2P^6 3S^2 3P^6 4S^2 3d^10 4P^6 5S^2 4d^10 5P^5
when Krypton is the noble gas in the row above iodine in the periodic table,
we can change 1S^2 2S^2 2P^6 3S^2 3P^6 4S^2 3d^10 4P^6 by the symbol
[Kr] of Krypton.
So we can write the electron configuration of Iodine:
[Kr] 5S^2 4d^10 5P^5
The correct answer is particle pollution.
Acids react with calcium carbonate and more specifically carbonate to form carbon dioxide. An acid will give protons to the carbonate anion to produce carbonic acid which then decomposes into carbon dioxide and water. I hope this helps. Let me know if anything is unclear.
